Alcohols Physical Properties : Alcohols have higher boiling points than ethers and alkanes of similar molar masses due to hydrogen bonding. Alcohols with up to four carbon atoms are soluble in water. Chemical Properties : Alcohols can be oxidized to form aldehydes (primary alcohols) or ketones (secondary alcohols). Tertiary alcohols resist oxidation. Common Reactions : Formation : Hydration of alkenes, fermentation of sugars. Reactions : Dehydration to form alkenes or ethers, oxidation to form aldehydes or ketones 1 . Ethers Physical Properties : Ethers have lower boiling points than alcohols due to the absence of hydrogen bonding. They are relatively inert and good solvents. Chemical Properties : Ethers are generally unreactive but can form peroxides upon prolonged exposure to air. Common Reactions : Formation : Dehydration of alcohols. Reactions : Cleavage by strong acids to form alcohols and alkyl halides 1 . Ketones Physical Properties : Ketones have moderate boiling points and are polar, making them good solvents. Chemical Properties : Ketones are less reactive than aldehydes but can undergo nucleophilic addition reactions. Common Reactions : Formation : Oxidation of secondary alcohols. Reactions : Reduction to secondary alcohols, nucleophilic addition to form alcohols 2 . Aldehydes Physical Properties : Aldehydes have higher boiling points than alkanes but lower than alcohols. They are polar and often have distinctive odors. Chemical Properties : Aldehydes are highly reactive and can undergo oxidation and nucleophilic addition. Common Reactions : Formation : Oxidation of primary alcohols. Reactions : Oxidation to carboxylic acids, reduction to primary alcohols, nucleophilic addition to form alcohols 2 . Thiols Physical Properties : Thiols have lower boiling points than alcohols and often have strong, unpleasant odors. Chemical Properties : Thiols are more acidic than alcohols and can form disulfides. Common Reactions : Formation : Substitution reactions of alkyl halides with hydrogen sulfide. Reactions : Oxidation to form disulfides, nucleophilic substitution 1 . Glycols Physical Properties : Glycols, such as ethylene glycol, have high boiling points and are hygroscopic. Chemical Properties : Glycols can form hydrogen bonds and are good solvents. Common Reactions : Formation : Hydroxylation of alkenes. Reactions : Oxidation to form aldehydes or carboxylic acids 1 . Phenols Physical Properties : Phenols have higher boiling points than alcohols due to hydrogen bonding and are slightly soluble in water. Chemical Properties : Phenols are more acidic than alcohols and can undergo electrophilic aromatic substitution. Common Reactions : Formation : Extraction from coal tar or synthesis from benzene derivatives. Reactions : Electrophilic substitution to form nitrophenols or halophenols, oxidation to quinones 2 . 1 : Chemistry LibreTexts 2 : CH105: Chapter 9 - Organic Compounds of Oxygen Further Explanation and Details from Summary Electrophilic Substitution Reactions Definition : In electrophilic substitution reactions, an electrophile replaces a functional group in a compound, typically an aromatic ring 1 . Electrophile : An electrophile is a chemical species that forms bonds by accepting an electron pair. They are electron-deficient and often positively charged or neutral with empty orbitals 2 . Mechanism : Generation of Electrophile : An electrophile is generated, often using a Lewis acid catalyst. Formation of Carbocation : The electrophile attacks the aromatic ring, forming a carbocation intermediate. Deprotonation : The intermediate loses a proton to restore aromaticity 1 . Examples : Nitration, sulfonation, halogenation, and Friedel-Crafts alkylation/ acylation 3 . Nucleophilic Substitution Reactions Definition : Nucleophilic substitution reactions involve a nucleophile replacing a leaving group in a molecule 4 . Nucleophile : A nucleophile is a chemical species that donates an electron pair to form a covalent bond. They are electron-rich and often negatively charged or neutral 5 . Mechanisms : SN1 (Unimolecular) : Two-step process where the leaving group departs first, forming a carbocation intermediate, followed by nucleophilic attack 4 . SN2 (Bimolecular) : One-step process where the nucleophile attacks the substrate simultaneously as the leaving group departs, leading to inversion of configuration 6 . Examples : Hydrolysis of alkyl halides, substitution reactions in alkyl halides 4 . Hydroxylation of Alkenes Definition : Hydroxylation of alkenes is an oxidation reaction that introduces hydroxyl groups (-OH) into the molecule. Mechanism : Epoxidation : Alkenes react with peroxy acids to form epoxides. Hydrolysis : Epoxides undergo acid-catalyzed ring-opening to form 1,2-diols (glycols). Reagents : Common reagents include osmium tetroxide (OsO₄) and potassium permanganate (KMnO₄) for syn dihydroxylation. 6 : Chemistry LibreTexts 4 : Nucleophilic substitution - Wikipedia 2 : Electrophile - Wikipedia 1 : Electrophilic Substitution Reaction - BYJU’S 5 : Nucleophile - Wikipedia 3 : Electrophilic Aromatic Substitution: The Six Key Reactions : Chemistry LibreTexts : Chemistry LibreTexts : Hydroxylation - Vocab, Definition, and Must Know Facts - Fiveable