Aldehydes and Ketones

aldehydes

RCHO (al)

ketones

R-CO-R (one)

Acetone

CH3COCH3

benzylaldehyde

Ph-CHO

which one is more reactive, aldehydes or ketones?

aldehyde

Formaldehyde

methanal

propionaldehyde

propanal

solubility in water lists

acids > alcohols > aldehydes + ketones > alkanes

how to synthesize aldehydes

oxidation of secondary alcohol

ozonolysis

oxymercuration

hydroboration

organocupurate/DIBAL-H + acid halides

DIBAL-H

disabutylaluminum hydride

strong reducing agents

LiAlH4

weak reducing agent

Sodium Borohydride (NaBH4)

- Can only reduce aldehydes, ketones, and acids to alcohol

why are aldehydes more reactive

is is less sterically hindered and forms a less stable carbocation

strong acids make

weak conjugate bases

weak acids make

strong conjugate bases

Organometalics

RLi, R-MgBr

PTSA

p-toluenesulfonic acid

Reagents for Hydroboration-Oxidation

1. BH3, THF

2. H2O2, NaOH

Reagents for aldol condensation

NaOH, H2O, heat

reagents for reduction

H2/Pt or Ni

NaBH4/H2O

LiAlH4/H2O

DIBAL-H

Reagents for nucleophilic addition

alcohol, organometallics, Grignard, amines, ammonia

nucleophilic addition reactions

Grignard, imines and enamine formation, acetal formation, hydride addition, halohydrins

2,4 DNP test

test for aldehydes and ketones

tollene's test

silver mirror test, checks for aldehydes

Reagents for wolf kishner

hydrazine/LDA to produce alkane

Cannizzaro Reaction

OH- with no alpha protons to produce alcohol and acid

clemmenson reaction

Zn/Hg+ in HCl to produce alkane

witting reaction

1. Ph3P-CH2 (phosphonium ylide) to produce alkene

reagents for acid chloride to aldehyde

DIBAL-H

reagents for acid chloride to ketone

(CH3)2Li

molecular weight of benzaldehyde

106g/mol

molecular weight of acetone

58g/mol

Dibenzalacetone

product of 2 benzaldehyde and 1 acetone

color of dibenzalacetone

bright yellow