CHEM 2370, Chapter 9, Exam 4

epoxide

oxygen in a three membered ring, unstable + ring strain

phenol

benzene ring with R group attached

benzyl

benzene ring with R group on a methyl group

ether

oxygen with 2 R groups

Boiling point increases with

lower degree alcohols bc steric hindrance allows easier hydrogen bonding

Williamson Ether Synthesis: conditions

SN/SB alkoxide and a primary alkyl halide

Williamson Ether Synthesis: mechanism

oxygen on alkoxide takes R group from alkyl halide as the halogen leaves

Synthesis of unhindered alkoxide for Williamson Ether Synthesis

2° alcohol + NaH → isopropyl attached to ONa + H2 gas

halohydrin

OH and halide on adjacent carbons

Williamson Ether Synthesis: halohydrin form mechanism

acid base reaction where NaH takes H from hydroxyl group on Halohydrin → SN2 reaction as O- forms an epoxide as halogen leaves

Williamson Ether Synthesis: halohydrin form products

epoxide

Williamson Ether Synthesis: halohydrin form reaction type

acid base → SN2 (inversion)

Williamson Ether Synthesis: halohydrin form conditions

alkane with hydroxyl group and halogen on adjacent carbons (anti) + NaH

pyridine

benzene ring with Nitrogen as connecting point

Acid-Catalyzed Dehydration w/o rearrangement: type of reaction

addition-elimination → acid-base → E2

Acid-Catalyzed Dehydration w/o rearrangement: mechanism

hydroxyl group takes POCl3 as pi bond on partially negative O breaks → lone pair on O- on P turns into pi bond again as Cl leaves, O from hydroxyl is positive → LP on pyridine takes H from O+ → LP on pyridine takes H from highest degree adjacent carbon as OPCl2 leaves → alkene forms from absent H

Alcohols and HX: mechanism

ROH + HX → ROH2+ → RX

Alcohols and HX: conditions

alcohol and HBr, HI, or HCl (AND ZnCl2)

Alcohols and HX: type of reaction

SN2 if methyl or 1°, SN1 if 2° or 3° w/ rearrangement

Other OH → alkyl halide conversions: SOCl2 mechanism

1°/2° OH + SOCl2 + pyridine → SN2 rxn, alkyl chloride

Other OH → alkyl halide conversions: PBr3 mechanism

1°/2° OH + PBr3 → alkyl bromide

Alcohols into Tosylate Group: conditions

alcohol + TSCl (p-Toluene Sulfonyl Chloride)/MsCl (mesyl chloride)/TfCl (triflic anhydride) + pyridine

Alcohols into Tosylate Group: mechanism

O from hydroxyl attaches to S as a pi bond in attached O breaks and makes it O- → O- reforms pi bond with LP as Cl leaves, O from OH group is positive → pyridine takes H from positive hydroxyl → left with retained OTs group on alkane

Alcohols into Tosylate Group: sulfonyl groups possible

TsCl, MsCl, TfCl → large molecule with central sulfide

Ether to Alkyl Halide: conditions

ether + strong acid + it’s conjugate base (ether + 2HX)

Ether to Alkyl Halide: mechanism

ether + 2HX → ROH + RX + HX → RX + RX + H2O

Ether to Alkyl Halide: 3° mechanism type

SN1 mechanism

Ether to Alkyl Halide: 1° mechanism type

SN2 mechanism

Ether to Alkyl Halide: outlier form

ether attached to a benzene ring + 2HX → OH on benzene ring + X on alkane from opposite side of ether + HX

BLAM

Base will attack Least substituted carbon under basic conditions, Acid will attacked Most substituted carbon under acidic conditions

Epoxide in Acid: mechanism

epoxide takes H from acid and becomes positive → CB of acid attacks most substituted carbon as ring breaks → H from positive H2O is taken by CB

Epoxide in Acid: reaction type

acid base → SN2 rxn→ sometimes acid base again

Epoxide in Base: mechanism

base attacks least substituted carbon of epoxide as ring breaks and epoxide O becomes negative → O- takes H from CA of base

Synthesis of Epoxides from Alkenes and Peroxy Acids: mechanism

alkene + peroxy acid (mCPBA) → epoxide on wedges + EN