alcohols and phenols

Methanol formation

Phenol

the word phenol is the name both of the specific compound (hydroxybenzene) and of the class of compounds.

alternate IUPAC name?

Allyl alcohol

alternate IUPAC name?

tert-butyl alcohol

alternate IUPAC name?

ethylene glycol

alternate IUPAC name?

glycerol

Ka (acidity constant formula)

K_a and pK_a relationship with acidity

bigger K_a and smaller pK_a = more acidic and vice versa for bases

oxonium ion ( formed by weak base undergoing revers protonation ( accepting proton)

alkoxide ion (formed by weak acid donating a proton to H2O (also generates H3O+)

alkene hydration (Hydroboration–oxidation)

• reagents

(syn, non-markovnikov)

1. BH₃ and THF

2. H₂O₂ and OH

alkene hydration (oxymercuration– demercuration)

• reagents ?

(markovnikov)

1. Hg(OAc)₂, H₂O

2. NaBH₄

direct hydroxylation

• reagents

• OsO₄ and pyridine

• NaHSO₃ and H2O

cis 1,2 diol

make a trans 1,2 diol

reagents?

1. RCO₃H, CH₂Cl₂

2. H3O+

with reducing agent

reduces to ?

Aldehyde and ketone reduction reagent

much more reactive and dangerous alternative reagent for aldehyde and ketone reduction

reduced to

what reduces all carbonyl groups

LiAlH₄

primary alcohol prepared by

reduction of an aldehyde, an ester , or a carboxylic acid

secondary alcohol prepared by

reduction of a ketone

adds OH and R to carbonyl carbon

Grignard reagent

• primary alcohol

Grignard reagents with esters and their similarities to esters with LiAlH₄

adds 2 R groups , just as LiAlH4 reduction of an ester adds two hydrogens

• ester - MgX

When do carboxylic acids react with Grignard reagents to give ketones

if first treated with i-Pr2NMgCl-LiCl (turbo-Hauser base)

general Grignard reagent reaction

Grignard reagent + x = 1 alcohol

x = formaldehyde

Grignard reagent + x = 2 alcohol

X= Aldehyde

Grignard reagent + x = 3 alcohol

X= ketone

tertiary alcohols into Alkyl Halides

• reagents

• mechanism

• HBr/ HCl

• SN1

Primary and secondary alcohols to alkyl halide

• mechanism

• reagents

• SN2

• SOCl₂ or PBr₃

Alcohols into Tosylates

• which bond is broken

• reagent

• O-H

• p-TosCl

Tertiary alcohol to alkene (acid catalyzed reaction)

• reagents

stereochem of acid catalyzed reactions

follow Zaitsev’s rule and yield the more stable alkene as the major product. (more substituted)

acid-catalyzed dehydration of tertiary alcohol to yield an alkene(mechanism)

• intermediate( E1 mechanism)

milder way to dehydrate alcohol(turn to alkene)

dehydration of secondary and tertiary alcohols by reaction with POCl3

OH converted to ?

mechanism

• –OPOCl2

• E2 ( follows E2 rules {leaving group have to be trans to each other (antiperiplanar })

Direct carboxylic acid (alcohol) to ester

reagent ?

strong catalyst

Indirect: carboxylic acid to ester by first converting carboxylic acid chloride

reagent ?

1. SOCl₂

2. Ch₃OH

oxidizes to

oxidizes to ?

oxidizes to ?

no reaction

Reagents to oxidize primary alcohol to

• aldehyde

• carboxylic acid

• Dess- Martin periodinane , CH₂Cl₂

• CrO₃ , H3O+ and acetone

Primary alcohols are oxidized to carboxylic acids by …

KMnO4 in a basic aqueous solution

secondary alcohols oxidation to what?

• reagents

Ketones

• Dess-Martin periodinane

• CH₂Cl₂

alcohol protection

stopping one functional group in a molecule form interfering with an intended reaction on another functional group elsewhere in the same molecule

alcohol protection method

chlorotrimethylsilane, and a base (CH₃CH₂)₃N

mechanism for alcohol protection with (CH₃)₃SiCl

SN2 (cl leaves and R-O binds at the same time )

regenerate alcohol from trialkylsilylethers

• reagent

Bu₄NF

modern phenol formation from Isopropyl benzene (cumene)

1. O₂/heat => peroxide

2. H₃O+

mechanism of phenol formation by acid catalyzed rearrangement of cumene hydroperoxide

phenol oxidation

• reagent

• product

• fremy’s salt (KSO₃)₂NO or Na₂Cr₂O₇

• quinone

quinone to hydroquinone

• reagent

• SnCl₂, H2O

NMR of phenols

the –OH signal of a tertiary alcohol (R3COH) is unsplit, the signal of a secondary alcohol (R2CHOH) is split into a doublet, and the signal of a primary alcohol (RCH2OH) is split into a triplet.

alpha cleavage

C–C bond nearest the hydroxyl group is broken