Alcohols and Phenols Theory and Reactions

Vocabulary flashcards covering preparation methods, named reactions, reagents, mechanisms, and distinguishing tests for alcohols and phenols based on lecture notes.

Hydroboration-Oxidation

A method to synthesize primary alcohols from terminal alkenes by reaction with diborane ($B_2H_6$) followed by basic hydrogen peroxide ($NaOH, H_2O$), yielding an anti-Markovnikov hydration product.

Oxymercuration-Demercuration

The preparation of alcohols from alkenes by treatment with mercuric acetate ($Hg(OCOCH_3)_2$) and water, followed by reduction with sodium borohydride ($NaBH_4$), yielding Markovnikov addition without carbocation rearrangement.

Alkene Oxidation by $SeO_2$

An allylic hydroxylation reaction where selenium dioxide ($SeO_2$) selectively oxidizes an allylic carbon of an alkene into an allylic alcohol.

Grignard Reaction with Formaldehyde

The nucleophilic addition of a Grignard reagent ($RMgX$) to formaldehyde ($HCHO$) followed by acid hydrolysis ($H_3O^+$) to exclusively produce a primary ($1^\circ$) alcohol.

Grignard Reaction with Ketones

The nucleophilic addition of a Grignard reagent ($RMgX$) to a ketone followed by acid hydrolysis ($H_3O^+$) to yield a tertiary ($3^\circ$) alcohol.

Reaction of RMgX with Phosgene ($COCl_2$)

A pathway consisting of two nucleophilic substitutions followed by one nucleophilic addition of $RMgX$ to phosgene ($COCl_2$) to form a symmetrical tertiary alcohol ($R_3C-OH$).

Reaction of RMgX with Diethyl Carbonate

The reaction of a Grignard reagent with diethyl carbonate ($EtO-CO-OEt$) involving two nucleophilic substitutions and one nucleophilic addition to yield a symmetrical tertiary alcohol.

Reaction of RMgX with Ethyl Formate ($HCOOEt$)

A reaction involving one nucleophilic substitution and one nucleophilic addition of Grignard reagent to ethyl formate to form a symmetrical secondary alcohol.

Bouvault-Blanc Reduction

A reduction method using sodium and ethanol ($Na / EtOH$) to reduce aldehydes and ketones into primary and secondary alcohols, or esters into two moles of alcohols (requiring $4\text{ moles of Na}$ per ester).

Relative Reducing Power of $LiAlH_4$ vs. $NaBH_4$

$LiAlH_4$ is a stronger reducing agent than $NaBH_4$ because aluminum is less electronegative than boron and $LiAlH_4$ is more ionic, enabling it to reduce carboxylic acids, esters, and anhydrides, whereas covalent $NaBH_4$ cannot.

Williamson's Etherification (Dehydration)

The intermolecular dehydration of an alcohol using concentrated sulfuric acid ($H_2SO_4$) at $140^\circ\text{C}$ to yield a symmetrical ether via a substitution pathway.

Williamson's Synthesis

An $S_N2$ reaction between a metal alkoxide ($R-O^-Na^+$) or phenoxide and a primary alkyl halide ($R-CH_2-X$) to form an ether.

Williamson's Esterification

The acid-catalyzed condensation of an alcohol with a carboxylic acid using concentrated $H_2SO_4$ or anhydrous gas-phase $HCl$ to synthesize an ester with the loss of water.

Acylation of Alcohols

The conversion of alcohols into esters using acid chlorides or anhydrides in the presence of an organic base ($Et_3N$ or pyridine) to absorb released $HCl$; it is faster than esterification because chloride ($Cl^-$) is a better leaving group than hydroxide ($OH^-$).

Jones Reagent

Chromium trioxide in aqueous sulfuric acid ($CrO_3 / H^+$), a strong oxidizing agent that oxidizes primary alcohols to carboxylic acids and secondary alcohols to ketones.

Collins Reagent

A complex of chromium trioxide and pyridine ($CrO_3 / Py$) used for the mild oxidation of alcohols.

PCC (Pyridinium Chlorochromate)

A mild oxidizing agent prepared from pyridine, $HCl$, and $CrO_3$ that selectively oxidizes primary alcohols to aldehydes without continuing oxidation to carboxylic acids.

$MnO_2$ Oxidation

A mild, selective oxidation process wherein manganese dioxide ($MnO_2$) oxidizes exclusively allylic and benzylic alcohols into their corresponding carbonyl compounds.

Lucas Reagent

A solution of anhydrous $ZnCl_2$ in concentrated $HCl$ used to distinguish alcohols based on the rate of turbidity formation ($3^\circ$ alcohol reacts immediately, $2^\circ$ in $5\text{ to }10\text{ minutes}$, and $1^\circ$ requires $10\text{ to }30\text{ minutes}$).

Victor Meyer Test

A chemical test to differentiate alcohols by sequential reaction with $P/I_2$, $AgNO_2$, $HNO_2$, and alkali ($NaOH$), producing a red color for primary ($1^\circ$), blue for secondary ($2^\circ$), and colorless for tertiary ($3^\circ$) alcohols.

Iodoform Test

A haloform reaction of methyl ketones or secondary alcohols having a $CH_3-CH(OH)-$ group with $I_2/OH^-$, producing a characteristic yellow precipitate of iodoform ($CHI_3$); ethanol is the only primary alcohol that gives a positive result.

Pinacol

A symmetrical vicinal diol specifically identified as 2,3-dimethylbutane-2,3-diol, prepared by the reductive dimerization of acetone with magnesium amalgam ($Mg/Hg$) and water.

Pinacolone

The ketone product 3,3-dimethylbutan-2-one formed from the acid-catalyzed rearrangement of pinacol.

Pinacol-Pinacolone Rearrangement

The acid-catalyzed conversion of a vicinal diol (glycol) into a ketone via protonation, loss of water to generate a carbocation, and a subsequent 1,2-alkyl or aryl shift.

Oxidative Cleavage of Glycols

The selective cleavage of the $C-C$ bond in 1,2-diols (or $\alpha$-hydroxy carbonyls) using periodic acid ($HIO_4$) to produce carbonyl fragments and iodic acid ($HIO_3$).

Cumene Process

An industrial method to prepare phenol and acetone by aerial oxidation of isopropylbenzene (cumene) to cumene hydroperoxide followed by acid-catalyzed cleavage.

Picric Acid

The common name for 2,4,6-trinitrophenol, a highly acidic organic compound that acts as a strong acid despite containing no carboxylic acid groups.

Schotten-Baumann Reaction

The acylation or benzoylation of phenols (or aromatic amines) using benzoyl chloride or an acid chloride in the presence of an aqueous or amine base (such as pyridine or $Et_3N$).

Ferric Chloride ($FeCl_3$) Test

A qualitative color test in which enols and phenols react with neutral ferric chloride ($FeCl_3$) solution to form deep violet, green, or blue coordination complexes.

Gattermann Aldehyde Synthesis

The formylation of phenol by treatment with hydrogen cyanide ($HCN$) and hydrochloric acid ($HCl$) in the presence of a Lewis acid, followed by hydrolysis to yield 4-hydroxybenzaldehyde.

Kolbe's Schmidt Reaction

The carboxylation of sodium phenoxide by carbon dioxide ($CO_2$) under pressure followed by acidification to produce salicylic acid (2-hydroxybenzoic acid).

Reimer-Tiemann Reaction

The ortho-formylation of phenol by heating with chloroform ($CHCl_3$) and aqueous $NaOH$ via a dichlorocarbene intermediate ($:CCl_2$) to produce salicylaldehyde.

Fries Rearrangement

The Lewis acid-catalyzed ($AlCl_3$) thermal rearrangement of phenolic esters into ortho- and para-hydroxy aryl ketones, where the ortho isomer is thermodynamically controlled and stabilized by intramolecular hydrogen bonding.

Elbs Persulfate Oxidation

The oxidation of monohydric phenols with potassium persulfate ($K_2S_2O_8$) in alkaline solution followed by acid hydrolysis to yield dihydric phenols (hydroquinones).

Phthalein Reaction

The condensation of phthalic anhydride with two equivalents of phenol in the presence of concentrated sulfuric acid to yield phenolphthalein, an acid-base indicator.

Azo Coupling Reaction

An electrophilic aromatic substitution where a diazonium salt (diazobenzene) reacts with electron-rich aromatic compounds like phenols in slightly basic medium to produce colored azo compounds.

Bakelite

A cross-linked thermosetting condensation polymer synthesized by the acid- or base-catalyzed reaction of phenol with formaldehyde.

Hexamine

Hexamethylenetetramine ($(CH_2)_6N_4$), a crystalline polycyclic amine prepared by the condensation of formaldehyde with ammonia ($HCHO + NH_3$), used as a curing or cross-linking agent.

Claisen Rearrangement

A concerted intramolecular thermal [3,3]-sigmatropic rearrangement of allyl aryl ethers into ortho-allylphenols (or para-allylphenols if the ortho positions are blocked).

Bouveault-Blanc Reduction

The reduction of carbonyl compounds (aldehydes, ketones, or esters) to alcohols using sodium metal in ethanol ($\text{Na}/\text{EtOH}$). One mole of carbonyl requires two moles of $\text{Na}/\text{EtOH}$, while one mole of ester requires four moles of sodium.

Lucas Reagent

A solution of anhydrous zinc chloride ($\text{ZnCl}_2$) and concentrated hydrochloric acid ($\text{HCl}$) used to classify alcohols. Tertiary ($3^\circ$) alcohols react immediately to produce a white emulsion, secondary ($2^\circ$) alcohols react in $5$ to $10\,\text{min}$, and primary ($1^\circ$) alcohols react in $10$ to $30\,\text{min}$.

Pinacol

A symmetrically substituted vicinal diol systematically named $2,3\text{-dimethylbutane-}2,3\text{-diol}$, having the chemical formula $\text{CH}_3\text{-C}(\text{CH}_3)(\text{OH})\text{-C}(\text{CH}_3)(\text{OH})\text{-CH}_3$.

Pinacolone

A ketone systematically named $3,3\text{-dimethylbutan-}2\text{-one}$ ($\text{CH}_3\text{-CO-C}(\text{CH}_3)_3$), formed via the acid-catalyzed rearrangement of pinacol.

Pinacol-Pinacolone Rearrangement

The acid-catalyzed conversion of a vicinal diol into a ketone involving protonation, dehydration to form a carbocation, and a subsequent $1,2\text{-shift}$ (such as a methyl or phenyl migration) driven by resonance stabilization from the adjacent oxygen atom.

Periodic Acid Cleavage ($\text{HIO}_4$ Cleavage)

The oxidative cleavage of vicinal diols ($1,2\text{-glycols}$) and $\alpha\text{-hydroxy}$ carbonyl compounds using periodic acid ($\text{HIO}_4$) to produce carbonyl fragments and iodic acid ($\text{HIO}_3$).

Pyridinium Chlorochromate (PCC)

A mild oxidizing reagent prepared from pyridine, $\text{HCl}$, and $\text{CrO}_3$ that selectively oxidizes primary alcohols to aldehydes without continuing oxidation to carboxylic acids.

Jones Reagent

A solution of chromium trioxide in dilute sulfuric acid ($\text{CrO}_3/\text{H}^+$) used for the strong oxidation of primary alcohols to carboxylic acids and secondary alcohols to ketones.

Collins Reagent

A complex of chromium trioxide with pyridine ($\text{CrO}_3/\text{Py}$) utilized for the oxidation of alcohols to carbonyl compounds.

Iodoform Test

A chemical test employing iodine and base ($\text{I}_2/\text{OH}^-$) to detect acetaldehyde, methyl ketones ($\text{R-CO-CH}_3$), or secondary alcohols containing the $\text{CH}_3\text{-CH}(\text{OH})-$ group by the precipitation of a yellow solid, triiodomethane ($\text{CHI}_3$).

Victor Meyer Test

A diagnostic method to differentiate primary, secondary, and tertiary alcohols through successive treatments with $\text{P} + \text{I}_2$, $\text{AgNO}_2$, $\text{HNO}_2$, and $\text{NaOH}$, resulting in a red, blue, or colorless/white solution, respectively.

Williamson's Ether Synthesis

The nucleophilic substitution reaction between an alkoxide or phenoxide ion ($\text{R-O}^-\text{Na}^+$) and an unhindered primary alkyl halide ($\text{R'-X}$) to synthesize symmetrical or unsymmetrical ethers.

Williamson's Esterification

The reversible reaction between an alcohol and a carboxylic acid in the presence of concentrated $\text{H}_2\text{SO}_4$ and gaseous $\text{HCl}$ to form an ester and water.

Lactide

A cyclic diester formed by the intermolecular condensation and loss of water from two molecules of an $\alpha\text{-hydroxy}$ carboxylic acid upon heating.

Lactone

An intramolecular cyclic ester formed spontaneously upon heating $\gamma\text{-hydroxy}$ or $\delta\text{-hydroxy}$ carboxylic acids through internal dehydration.

Schotten-Baumann Reaction

The acylation or benzoylation of phenols or amines using benzoyl chloride ($\text{PhCOCl}$) in the presence of an organic base such as pyridine or triethylamine ($\text{Et}_3\text{N}$) to neutralize the byproduct $\text{HCl}$.

Reimer-Tiemann Reaction

The ortho-formylation of phenol by treatment with chloroform ($\text{CHCl}_3$) and aqueous sodium hydroxide ($\text{NaOH}$) via an electron-deficient dichlorocarbene ($\text{:CCl}_2$) intermediate, affording salicylaldehyde after acidification.

Kolbe-Schmitt Reaction

The carboxylation of sodium phenoxide with carbon dioxide ($\text{CO}_2$) under alkaline conditions, which upon acidification yields salicylic acid as the major product.

Fries Rearrangement

The aluminum chloride ($\text{AlCl}_3$)-catalyzed rearrangement of phenyl esters into ortho- and para-hydroxy aryl ketones, where the kinetically controlled para-isomer dominates at low temperatures and the thermodynamically stable ortho-isomer dominates at high temperatures.

Elbs Persulphate Oxidation

The oxidation of monohydric phenols to para-dihydric phenols (quinol / benzene-$1,4\text{-diol}$) using potassium persulfate ($\text{K}_2\text{S}_2\text{O}_8$) in basic or acidic medium.

Gattermann Aldehyde Synthesis

The formylation of phenol with hydrogen cyanide ($\text{HCN}$) and hydrochloric acid ($\text{HCl}$) in the presence of a Lewis acid catalyst, yielding an aldimine intermediate that hydrolyzes to para-hydroxybenzaldehyde.

Claisen Rearrangement

An intramolecular thermal $[3,3]\text{-sigmatropic}$ rearrangement of allyl aryl ethers (such as allyl phenyl ether) upon heating to form ortho-allylphenols via allylic inversion.

Picric Acid

$2,4,6\text{-trinitrophenol}$; a strongly acidic phenolic compound lacking carboxylic groups, prepared commercially by first sulfonating phenol with concentrated $\text{H}_2\text{SO}_4$ and then nitrating with concentrated $\text{HNO}_3$ to prevent oxidative breakdown.

Phenolphthalein

A triphenylmethane dye synthesized by the condensation of phthalic anhydride with two equivalents of phenol in concentrated $\text{H}_2\text{SO}_4$, widely used as an acid-base indicator.

Bakelite

A thermosetting, cross-linked condensation polymer formed by the step-growth reaction of phenol with formaldehyde ($\text{HCHO}$) in the presence of an acid or base catalyst.

Hexamine

A cage-like organic compound with the formula $(\text{CH}_2)_6\text{N}_4$ (hexamethylenetetramine), prepared by the thermal reaction of formaldehyde ($\text{HCHO}$) with ammonia ($\text{NH}_3$), used as a crosslinking and curing agent.

Cumene Process

The industrial synthesis of phenol and acetone via the aerial oxidation of cumene (isopropylbenzene) to cumene hydroperoxide, followed by acid-catalyzed rearrangement and cleavage.

Azo Coupling Reaction

An electrophilic aromatic substitution where a diazonium cation ($\text{Ph-N}_2^+$) couples with an activated aromatic ring such as phenol in slightly basic medium to yield a brightly colored azo dye.