CHEM219 / CHEM 219 Module 5 Exam Questions & Answers | Latest 2026–2027 Update | Principles of Organic Chemistry with Lab | Portage Learning | Verified Solutions

CHEM219 / CHEM 219 Module 5 Exam Questions & Answers | Latest 2026–2027 Update | Principles of Organic Chemistry with Lab | Portage Learning | Verified Solutions 2026 / 2027 Academic Year Q: Generic formula for alcohols Answer R-OH Q: phenol Answer hydroxy-substituted aromatic molecules (any compound with an -OH attached to a benzene ring) Q: IUPAC system rules for naming organic alcohols Answer - organic alcohols are named by replacing the suffix of the parent chain of the molecule with the suffix -ol - The parent chain is numbered so as to give the hydroxyl group the lowest possible number. (examples: 1-propanol, and cyclohexanol) - with unsaturated alcohols the -ol suffix comes last and takes priority when numbering the parent chain (2-propene-1-ol) - Molecules with more than one -OH group get a prefix describing the number of -OH groups added to the IUPAC name. (ethane-1,2-diol) Molecules with more than one -OH group polyols Q: IUPAC rules for phenols Answer - the suffix for an alcohol substituted benzene is "phenol" - start the numbering at the OH group (so OH is at the 1 position) (examples: phenol, 3-methylphenol, 2,4-dinitrophenol) Q: Why can alcohols form strong hydrogen bonds? Answer These attractions raise the amount of energy required to vaporize the liquid-phase molecules (boil), which translates into increased boiling point temperatures. Due to the presence of the hydroxyl group, as the O-H bond is highly polarized by the electronegative oxygen atom. This polarization places a + charge on the hydrogen atom and a - charge on the oxygen atom. The polarization in the O-H bond on one alcohol molecule becomes attracted to the polarization in the O-H bond of another alcohol molecule. Q: Why do alcohols have much higher boiling points than other molecules of similar molecular weight? Answer hydrogen bonding between alcohol molecules Q: Alcohol molecules can freely hydrogen bond to other molecules possessing what groups? Answer O-H, N-H, or S-H functional groupings Q: How does the water solubility of alcohol molecules change as the molecular weight changes? Answer Alcohol molecules of lower molecular weight are mostly soluble in water as a result of the ability to hydrogen bond to OH, NH, or SH groups. As the molecular weight or carbon chain length increases, the alcohol molecules become correspondingly less soluble in water. Q: How do alcohols and phenols act as weak acids and weak bases? Answer - acts as an acid by donating the O-H proton as H - acts as a base by accepting H+ using a lone pair on the O atom Q: amphoteric substances Answer Substances that can act as both acids and bases (alcohols and phenols) Q: Why is acid dissociation for most alcohols unfavorable (lies towards the left)? Answer Dissociation produces an alkoxide ion (the conjugate base of an alcohol), which is a very strong base. Q: How can you conduct acid-base reactions that favor the formation of weaker conjugate acids/bases? Answer To promote (favor) the formation of the alkoxide ion, the alcohol can be treated with sodium or potassium metal (Na or K) or a base that is stronger than the RO- ion produced. Q: protonation of an alcohol Answer - A specific type of elimination reaction. In a dehydration reaction, an alcohol molecule will lose H2O to form an alkene. Alcohols undergo a reaction known as dehydration when they When alcohols act as weak bases by using a lone pair on the oxygen atom of the hydroxyl group, alcohols can accept a proton when they are placed in an acidic environment. Q: What is the product of the protonation of an alcohol called? Answer alkyloxonium ion What is a Dehydration reaction for alcohols? Q: What happens during a dehydration reaction for alcohols? Answer are heated with strong mineral acids (like sulfuric or phosphoric). - the alcohol molecule loses the hydroxyl (OH) from one carbon (the α-carbon) and a hydrogen atom (H) from an adjacent (β) carbon. Q: What is the function of an acid during a dehydration reactions? Why does it do what it does? Answer To protonate the the OH group It does this to make it a better (more stable) leaving group because H2O is a neutral while hydroxide ion is strongly basic. Q: What type of mechanism is a dehydration reaction for a sterically bulky tertiary alcohol? Answer E1 mechanism Q: Steps of a dehydration reaction for a tertiary alcohol Answer - the OH group is pronated (the alcohol acts as a base and accepts a proton from the acid solvent onto its OH group) - the OH group disassociates, forming a carbocation - then water, acting as a base, removes a β-hydrogen to form the alkene. - The net result is that H and OH are removed (eliminated) from the original alcohol substrate. - products: an alkene and H3O+ Q: What type of mechanism is a dehydration reaction for a sterically non-bulky primary alcohol? Answer E2 mechanism Q: Why do primary alcohols dehydrate through the E2 mechanism? Answer Because these substrates do not form stable carbocation intermediates. Q: Steps of a dehydration reaction for a primary alcohol Answer - hydroxyl (OH) group is pronated by the solvent - a water molecule (from the solvent?) removes a β-hydrogen. - As the β-hydrogen is removed the bond H-C bond is broken and then there is a C=C bond formed between the β carbon and the α-carbon. - At the same time. the double bond kicks off the H2O molecule from the α-carbon - The net result is that H and OH are removed (eliminated) from the original alcohol substrate. - products: an alkene and H3O+ Q: What is the order of ease of dehydration of alcohol substrates? Answer 3° 2° 1° Tertiary alcohols require the least harsh reaction conditions (typically 25% aqueous acid and 60-80°C), whereas 1° alcohols require fully concentrated acid and temperatures approaching 200°C. Q: When can a single alcohol substrate produce more than one alkene product? Answer This occurs when a β-hydrogen can be removed from different carbons to create the C=C in different places on the parent chain. Q: Zaitsev's Rule Answer In cases where more than one alkene product is possible, the major product is always the alkene whose C=C has more alkyl groups attached. The greater the substitution (the number of alkyl groups) attached to the C=C, the more stable the alkene. Q: What type of reaction is it when alcohols are converted to alkyl halides? Answer A substitution reaction Replacing the hydroxyl group with a halogen Q: What are the different halides that can be used for Alcohols - Alkyl Halides Conversion? Answer - Conversion using Hydrogen Halides (HX) - Conversion using Phosphorus Halides (PX3) - Conversion using Thionyl Chloride (SOCl2) Q: What are the two ways the use of hydrogen halides promotes substitution? Answer 1. The acid protonates the hydroxyl group of the alcohol to make it a good leaving group. 2. The halide ions are good nucleophiles but weak bases, so substitution is promoted over elimination. What is the order of ease for reactivity of alcohols with hydrogen halides? Primary alcohols react much more slowly and require much more harsh reaction conditions. For example, the conversion of 1-butanol to 1-chlorobutane requires the use of Q: What conditions do the reactions of different alcohol structures require? Answer Tertiary Secondary Primary alcohols Tertiary alcohols react the fastest under the mildest conditions. Example: The reaction of 2 methyl-2-propanol with HCl. This reaction occurs by an SN1 mechanism (tertiary substrate) and can be performed at room temperature (R.T.) in as little as fifteen minutes. Secondary alcohols react at intermediate rates by either SN1 or SN2 mechanisms, depending on the structure of the specific alcohol. concentrated hydrochloric acid and a catalyst (typically zinc chloride) and strong heating for several hours to accomplish the same conversion. Primary alcohols react via an SN2 mechanism. How can the reaction of a primary alcohol converting into an alkyl halide via SN2 mechanism by influenced by a ZnCl2 solvent? Answer Primary alcohols react via an SN2 mechanism. The hydroxyl group of the alcohol is protonated and then displaced as a water molecule by a chloride ion. Zinc chloride can serve a similar role as that of a proton by accepting a lone pair from the hydroxyl oxygen atom. Zinc chloride also can dissociate to provide more chloride ions into the reaction mixture, thus increasing the concentration of the nucleophile and the rate of the overall reaction. With a Phosphorus trihalide reagent (PX3), which halides can be X? Answer Cl or Br This reaction is particularly efficient as one molecule of PX3 can convert three molecules of alcohol to the corresponding alkyl halide. Which alcohol structures can be converted to alkyl chlorides and bromides using Phosphorus trihalide reagents? Answer Primary and Secondary structures What is the stoichiometric benefit of Conversion using Phosphorus Halides (PX3)? Answer What is a byproduct of the conversion via phosphorus halides? Why is it beneficial for distillation? Answer A byproduct of the reaction is phosphorus acid (H3PO3), which has a rather high boiling point. This makes isolation of the (relatively) low boiling alkyl halide product easy by distillation. What is the molecular formula for the reagent thionyl chloride? Answer SOCL2 What does using Thionyl Chloride (SOCl2) for conversion of alcohols produce? Which type of structures can this conversion using SOCl2 be used on? Answer - used to convert alcohols to the corresponding alkyl chloride. - very efficient for primary and secondary alcohols. What is the advantage of using Conversion via Thionyl Chloride? Answer Although there is no stoichiometric advantage in this reaction (like with PX3), the advantage to this reaction is that the main byproduct (SO2) is formed as a gas and leaves the reaction mixture. Oxidation Answer Oxidation is recognized in organic molecules by increasing the oxygen content (the number of oxygen atoms) or the oxygen character (more bonds to oxygen). What kind of alcohol structures can go through oxidation? primary and secondary alcohols What are the products of oxidation of alcohols? Carbonyl containing compounds: Aldehydes, Ketones, Carboxylic Acids How does the oxidation of primary alcohols differ from the oxidation of secondary alcohols? Primary alcohols are initially oxidized to aldehydes, which can then be oxidized further to carboxylic acids. Secondary alcohols are oxidized to ketones. No further oxidation (outside of combustion, which destroys the molecule) is possible. This is added to a solution of the alcohol dissolved in acetone as the solvent. Chromic acid is a strong oxidizing agent and will oxidize primary alcohols to carboxylic acids without stopping at the aldehyde stage. Secondary alcohols are oxidized to ketones. There are various chemical reagents that can accomplish the oxidation of alcohols to carbonyl compounds. What are some chemical reagents for oxidation? chromic acid (H2CrO4) potassium permanganate (KMnO4) sodium hypochlorite (NaOCl) Jones' Reagent - what is it? What are its disadvantages? The mixture of chromium trioxide (CrO3) with aqueous sulfuric acid. Produces chromic acid (H2CrO4). One obvious disadvantage of using Jones' Reagent is that it is a strong oxidizer and will not permit the synthesis of aldehydes from primary alcohols. What benefit is PCC (pyridinium chlorochromate) for oxidation reactions? PCC will accomplish the oxidation for a primary alcohol to the aldehyde stage and stop there without further oxidation to the carboxylic acid. A disadvantage of using Jones' Reagent is that it is a strong oxidizer and will not permit the synthesis of aldehydes from primary alcohols (it will continue to the carboxylic acid stage). For this purpose, a mild oxidizing reagent known as PCC is used. How do tertiary alcohols react during oxidation reactions? Tertiary alcohols are unreactive in these types of oxidation reactions. Research into the mechanism of these types of oxidations has revealed that the alcohol must have at least one hydrogen attached to the carbon on the hydroxyl-bearing carbon. ethers All ethers are organic molecules in which two alkyl or aryl (R) groups are covalently bonded to a single oxygen atom. The generic formula for an ether is R-O R'. The R groups can be the same (symmetric ether) or they can be different (asymmetric ether). Nomenclature of Ethers and Epoxides Go to Module 5.3 alkoxy substituent an -OR group attached to the parent chain methoxy The name for a substituent attached to the parent chain of just O-CH3 Epoxides Three-membered cyclic ethers, composed of two carbon atoms and a single oxygen. Epoxides are also known as oxiranes. The small, three-membered ring of an epoxide is very highly strained (severe angle strain), and as a result, epoxides are useful in synthesis where atoms or groups can be added to the epoxide molecule using a ring-opening reaction. crown ethers Macrocyclic (large ring) polymeric ethers are known as crown ethers because their rings have a distinct repeating pattern that resembles a crown. Nomenclature for crown ethers The naming conventions for crown ethers follow the pattern "[x]crown-y", where "x" is a number that reflects the ring size, and "y" represents the number of oxygen atoms. The oxygen atoms are usually separated from one another by two carbon atoms. What is the special ability of crown ethers? Crown ethers are a special class of ethers, as they have the ability to solvate cations (+) within the interior cavity of their ring structures. The lone pairs of the oxygen atoms in the ring can bind to cationic species and hold them. The size of the ring controls which cations can fit into the cavity. This phenomenon is important because it allows ionic compounds to be dissolved in relatively non-polar organic solvents. Why do ethers have lower boiling points than that of an alcohol of the same molecular weight? Due to their atomic connectivity, ethers do not have any O-H covalent bonds and, thus, are incapable of forming hydrogen bonds with one another. The lack of intermolecular attraction causes ethers to boil at much lower temperatures than their constitutionally isomeric alcohols. The boiling point of an ether is very similar to a hydrocarbon of corresponding molecular weight What type of hydrogen bonds can ethers do? Although ethers cannot form hydrogen bonding attractions with molecules of each other, the lone pairs of electrons on the oxygen of an ether can form hydrogen bonds to molecules that have O-H, N-H, or S-H bonds as a part of their structure. In other words, ethers cannot donate hydrogen bonds but can accept them from other molecules. Ethers can accept hydrogen bonds from alcohols, and water. What happens to the water solubility of an ether as the size of the R groups of an ether increases? As the size of the R groups of an ether increases, the water solubility of the ether decreases as the hydrocarbon portion of the molecule overwhelms the ability of the molecule to make hydrogen bonds. Describe ethers as solvents Ethers are relatively inert compounds. For this reason, they are often used as solvents for reactions or to prepare solutions containing relatively reactive materials. Most organic compounds dissolve in ethers. Ethers as extraction solvents Used to isolate/collect organic compounds from their natural sources. The low boiling point of ethers makes them easy to remove from an extract. Volatility of ethers Ethers, in general, are volatile (low boiling point). This volatility presents a danger as well - most small ethers are highly flammable and should not be used in a location where sources of open flame are found (such as Bunsen or Fisher burners). Electrically operated heat sources or steam are used to heat ether-based (ethereal) solutions. Long-term exposure to oxygen in air can cause the formation of explosive peroxides in ethers. Why is the dehydration of alcohols to produce ethers limited to the synthesis of symmetric ethers from primary alcohols? If the desired ether is asymmetric, or the complexity of the R groups increases, the overall yield of the desired ether product is reduced. With the goal of forming more complex ethers (especially asymmetric ethers), what is one mode of preparation available but not the most preferred option? addition of alcohols to alkenes During this reaction an alcohol is used as the solvent instead of water and acts as the nucleophile, resulting in the overall addition of H (from the acid catalyst) and -OR (from the alcohol) across the double bond of the alkene, breaking the double bond and forming a more complex/asymmetrical ether. With the goal of forming asymmetric ethers, what mode of preparation preferred? What are the steps? Williamson Synthesis This method uses two steps to produce an asymmetric ether. 1. In the first step, an alcohol is converted to its conjugate base (alkoxide ion, RO-) usually by reacting the alcohol with sodium or potassium metal. 2. The alkoxide is then reacted as a nucleophile in an SN2 displacement, typically on an alkyl halide substrate. The net result of the two reactions is the formation of an ether where R does not = R'. What is necessary about the R and R' groups of a Williamson Synthesis in order for their to be a higher yield of product? The R' group would need to have a smaller steric bulk (primary or secondary), which would allow for the SN2 mechanism in the second step. If the R' group is sterically bulkier than the R group, it would have to go through an E2 mechanism which would have a smaller yield of product. what does "unhindered" mean? Less sterically bulky (primary or secondary strucutres) Although mostly inert, ethers can be forced to react under very specific reaction conditions (typically harsh/extreme conditions). The typical mode of reaction of an ether is .....? Cleavage What is the cleavage reaction of an ether? What type of molecule is used to perform the cleavage? Breaking apart of the ether by severing a C-O bond of the ether by an HX. Typically, ethers react with strong acids and heat to undergo cleavage. If the alkyl groups of the ether are unhindered, what mechanism will be used to sever the C O bond? The C-O bond can be broken by reaction with a halogen nucleophile in an SN2 reaction after protonation of the ether oxygen What happens during a cleavage reaction if the alkyl groups are unhindered? The halogen bonds to the less-hindered R group (creating the alkyl halide), and the oxonium ion is displaced to form an alcohol (containing the larger, more-hindered R group). What happens during a cleavage reaction if the alkyl groups are hindered (tertiary)? If the alkyl groups are bulky/sterically hindered (tertiary), the ether typically cleaves by an SN1 mechanism, as these groups can form the stable carbocation intermediate that defines the SN1 mechanism. In this case, the ether oxygen atom remains with the less-hindered alkyl group and the halide bonds to the more-hindered alkyl group. What are the initial products of the cleavage of an ether using HX? What happens is excess HX is present? The initial products of the cleavage of an ether using HX are one equivalent of alcohol and one equivalent of alkyl halide. If excess HX is present, the alcohol formed via cleavage may react to form another equivalent of alkyl halide. Cleavage reactions can be used to help determine the structure of complex, naturally occurring ethers because the products of the cleavage reaction are smaller and more easily analyzed fragments. Working backward from the fragments, the structure of the original ether can be deduced. What is a peroxyacid (or peracid) and what is it used for? A peroxyacid is analogous in structure to a carboxylic acid but contains an extra oxygen between the carbonyl and hydroxyl group. A reagent used to synthesis epoxides from alkenes. What happens during a epoxidation reaction? An alkene reacts with a peroxyacid to form an epoxide. - an oxygen is transferred from the peroxyacid to the alkene - the C=C p bond is broken and incorporates the oxygen atom as part of a three-membered ring. Why are epoxides more reactive than ethers? Due to the significant amount of ring strain in epoxides, they are much more reactive than regular ethers and undergo reactions through opening of the three-membered ring. What is a common way to open the three membered ring of a epoxides? Treat the molecule with aqueous acid (a mixture of acid and water). What happens during a reaction between epoxides and aqueous acid or alcohols? What is the product? - initial protonation of the epoxide oxygen - followed by a nucleophilic attack of water on one of the epoxide carbons - SN2 where the leaving group remains attached to the other carbon atom of the original epoxide ring The product of an acid-catalyzed ring opening of an epoxide is a diol, specifically a vicinal diol (two hydroxyl groups on adjacent carbons). vicinal diol two hydroxyl groups on adjacent carbons Alcohol Generic formula R-OH, defined by the presence of a Hydroxyl group (-OH). Organic derivatives of water, as one of the hydrogen atoms from the water molecule is replaced by an alkyl group. Phenols Hydroxyl group directly attached to a benzene ring Methyl Alcohol Only H atoms attached to the carbon bearing the-OH group Primary Alcohol one alkyl group attached to the carbon atom bonded to the -OH group Secondary Alcohol Two alkyl groups attached to the carbon atom bonded to the -OH group Tertiary Alcohol Three alkyl groups attached to the carbon atom bonded to the -OH group Boiling Point of Alcohols High due to Hydrogen bonding between the positively charged H and negatively charged O Alkoxide Ion conjugate base of an alcohol, very strong base Water solubility of alcohols As the carbon chain length increases alcohol becomes correspondingly less soluble in water. Alcohols Acidity/Basicity Can act as a weak base (accepting H+ using a lone pair on the O atom) or weak acid (donating the O-H proton as H+) Amphoteric a substance that can act as both an acid and a base Alkyloxonium Ion The conjugate acid of the alcohol is often called a protonated alcohol, Dehydration Loss of water. An alcohol molecule will lose H2O to form an ALKENE. Type of elimination reaction — lose the -OH from one C and H atom from the adjacent C. First step — alcohol acts as a base. Tertiary alcohols - E1 Primary alcohols - E2 All dehydration begins with... Protonation of the alcohol group. Order of ease of dehydration of alcohol substrates... 321 Tertiary require the least harsh conditions (typically 25% aqueous acid and 60-80 degrees C) whereas primary require fully concentrated acid and temperatures approaching 200 degrees C. If more than one alkene product is possible... The major product is the one whose C=C has more alkyl groups attached. ZAitsev's Rule The production of the more highly substituted alkene as the major product. Alcohols — Alkyl Halides -Substitution REaction , replacing the -OH with a halogen -Alcohol (R-OH) + Hydrogen Halide (H-X) —— alkyl halide (R-X) + water (H-OH) -the use of Hydrogen halides promotes the substitution in two ways 1. Acid protonates the -OH of the alcohol to make it a good leaving group 2. Halide ions are good nucleophiles but weak bases so substitution is promoted over elimination Order of Reactivity of Alcohols with HX 321 Primary Alcohols react via.... (With HX) Sn2 -OH group is protonated and then displaced as a water molecule by a chloride ion Secondary Alcohols react via... (with HX) Sn1 or Sn2 - depending on the structure of the specific alcohol Conversion using Phosphorous Halides (PX3) X= Cl or Br - Alcohol (3R-OH) + phosphorous trihalide (X2P-X) — alkyl halide (3R-X) + H3PO3 -particularly efficient as one molecule of PX3 can convert 3 molecules of alcohol to the corresponding alkyl halide -byproduct of the reaction is phosphorous acid Conversion using Thionyl Chloride (SOCl2) Alcohol (R-OH) + Thionyl Chloride (Cl-S=O-Cl) — alkyl Chloride (R-Cl) + SO2 ^ + HCl - very efficient with primary and secondary alcohols d/t the main byproduct (SO2) beig formed as a gas and leaving the reaction mixture. Oxidation to Aldehydes, Ketones and CArboxylic Acids Oxidation - increasing the oxygen content (number of oxygen atoms) or the oxygen character (more bonds to oxygen) -Primary Alcohols — aldehydes — Carboxylic Acids -SEcondary Alcohols —ketones -Tertiary - unreactive Jones Reagent Cromium Triioxide with aqueous sulfuric acid — Chromic Acid Disadvantage - strong oxidizer and wil not permit the synthesis of aldehydes from primary alcohols Oxidizing agents that convert alcohols to Carbonyl compounds Potassium Permanganate (KMnO4) Sodium Hypochlorite (NaOCl) PCC Oxidation of Alcohols Pyridinium Chlorochromate - oxidizes primary alcohols to the aldehyde stage and stop there without further oxidation to the Carboxylic acid. -Dichloromethane (CH2Cl2) is typically the solvent used for PCC oxidation o alcohols Ether Alkyl or Aryl group that are covalently bonded to a single O atom. Generic Formula : R-O-R' (R groups can be the same - symmetric or different - asymmetric) Epoxides Three-member Ed cyclic ethers - composed of two C atoms and a single O atom. Also known as Oxiranes. Very highly strained (severe angle strain) Useful in synthesis where atoms or groups can be added to the Epoxide molecule using a ring-opening reaction Macrocyclic Large ring polymer ethers Crown ethers - because their rings have a distinct repeating pattern [X]crown-y ; X= ring size ; y= number of oxygen atoms Crown Ethers Can solvate cations within theur interior cavity, size of the ring controls which cations can fit into the cavity, this allows ionic compounds to be dissolved in relatively non-polar organic solvents Properties of Ethers Clear, Colorless, with characteristic odors Lower BP than alcohols with similar molecular weights Cannot H bond Boiling point is similar to a hydrocarbon of corresponding molecular weight Can not form H bonds to each other, but can form H bonds to O-H, N-H or S-H to the lone pair of O As the R groups increase, water solubility decreases Ethers as Solvents Relatively inert Make excellent extraction solvents (used to isolate/collect organic compunds from theur natural sources) Low boiling point Highly flammable Preparation by Addition of Alcohols to Alkenes Williamson Synthesis Two steps to produce an asymmetric ether, in fist step alcohol is converted to its conjugate base, (Alkoxide ion RO-) by reacting the alcohol with sodium or potassium metal. The Alkoxide is then reacted as a nucleophile in an Sn2 displacement, typically on an alkyl halide substrate. Net result is an ether where R does not equal R. Typically primary or secondary only. Cleavage by HX Typical mode of reaction is cleavage (breaking apart of the ether by severing a C-O bond of the ether. Usually react with strong acids and heat. Tertiary - Sn1; ether O remains with the less-hindered alkyl group and the halid bonds to the more hindered alkyl group. Initial products of cleavage of an ether are an alcohol and an alkyl halide. Synthesis of expoxides from alkenes Use peracid (peroxyacid). Forms by transfer of the extra O to the alkene. C=C bond is broken and incorporates the O atom as a part of a 3 membered ring. Peroxyacid Analogous in structure to a Carboxylic acid but contains an extra oxygen between the carbonyl and hydroxy group Reactions of Expoxides with waters and alcohols Epoxides are much more reactive due to their ring strain. A common way to open the ring is to treat it with aqueous acid. Sn2 - initial protonation of the expoxide O , followed by nucleophilic attack of water on one of the epoxide Carbons. Vicinal Diol Product of an acid-catalyzed ring opening of an epoxide. Two hydroxyl groups on adjacent carbons. Aldehydes Presence of a carbonyl group (C=O) with at least one H attached to the carbonyl C and the remaining valence may be another H atom or an alkyl or aryl group. Ketones Presence of a carbonyl group (C=O), carbonyl C is directly connected to two other C based groups. IUPAC aldehyde nomenclature -al (suffix) Parent chain is named based in the number of C in the longest chain containing H C=O(formal group) IUPAC ketone nomenclature -one suffix Parent chain is the longest contiguous chain that contains the Carbonyl group, numbering begins at the end of the chain nearest the carbonyl carbon Nucleophilic Addition Attack of the nucleophile at the positive carbonyl carbon, this attack is typically followed by addition of a proton (hydrogen) to the carbonyl oxygen Dipole-dipole attractions Cause the molecules to associate with the + part of one molecule attracted to the - part of another. Stronger than van der walls forces, but weaker than H bonding. Aldehydes are reduced to... Primary alcohols Ketones are reduced to... Secondary alcohols Hydride transfer reducing agents Most widely used reagent to reduce aldehydes and ketones. They reduce aldehydes and ketones by producing hydride ion (H:-) in solution. Hydride ion is a potent nucleophile and can react with the carbonyl C of an aldehyde or ketone. Ex. Sodium Borohydride (NaBH4) Sodium Borohydride (NaBH4) Advantages - reduces all aldehydes and ketones. Stable and can be used in mixed aqueous systems. Very efficient as one Borohydride can transfer all 4 of its H atoms as hydride ions and reduce 4 carbonyls The difference between most additions of aldehydes and ketones is WHEN the proton gets bonded to the carbonyl carbon... Acidic environment - proton bonds to carbonyl O before the nucleophile attacks which makes the C=O more reactive towards nucleophilic attack and is useful when a weaker (uncharged) nucleophile is used. Basic Environment - the strong (typically negative) nucleophile attacks first, followed by subsequent protonation of the Alkoxide oxygen. Nomenclature of Carboxylic Acids -oic acid Numbering begins with carboxyl carbon atom