Organic chemistry ch. 17

Reduction

Increase in the # of H

H2, Pd-C

Only reduce alkenes, not carbonyls

H2 (xs), Pd-C

Completely reduces alkenes and carbonyls

NaBH4, MeOH

A mild reducing agent that reduces aldehydes to primary alcohols and ketones into secondary alcohols, followed by hydrolysis.

Will NaBH4, MeOH or 1) LiAlH4 2) H2O reduce OH?

No, NaBH4 and LiAlH4 will not reduce alcohols to other products.

1) LiAlH4 2)H2O or NaBH4, MeOH

What happens to leaving groups when NaBH4, MeOH or 1) LiAlH4 2) H2O is used?

The LG leaves and the reduction continues as normal.

How does NaBH4, MeOH and 1) LiAlH4 2) H2O react in the presence of NH?

NH stays and the carbonyl is kicked off

DIBAL-H and big boy

Soft reducing agents that stop at the aldehyde

DIBAL-H is selective for

Esters, acid chlorides, nitriles

Big Boy is selective for

Cl

PCC, DCM

Mild oxidizer, turns primary alcohols into aldehydes and secondary alcohols into ketones

Cr 6+/ CrO3/ Cr2O7 in H+

Strong oxidizer, turn primary alcohols into carboxylic acids and secondary alcohols into ketones

Ag2, NH4OH

Mild oxidizer, selective for aldehydes. Turns aldehydes into carboxylic acids

KMnO4

Strong oxidizer, turn primary and secondary alcohols into carboxylic acids, converts side chain db of ring into alcohols

KMnO4

What happens in an organolithium or Grignard reaction if there is a LG on the reactant?

The organometallic attacks twice

Cuprate functions

Soft oxidizer; 1,4 addition; acid halide to ketone, open least substituted C on epoxides

Organolithiums and Grignards

Hard oxidizing; 1.2 addition;

TBAF

Kicks off protecting group

TBDMS-Cl, imidazole

forms stable protecting group

Forms methyl group

1) (Me)2CuLi 2)H2O

adds a methyl group

Cuprates don’t react with

Aldehydes, ketones, carboxylic acids, esters

LiAlH4 2) H2O

Strong oxidizer

Counter clockwise is what configuration

S (H makes it switch to R)

imine and enamine rns occur in what solvent?

acetic acid

ch3co2-h pka

4.8

water pka

15.7

ch3ch2o-h pka

16

hc triple bond ch

25

H-H

35

CH2=CH2

44

CH3-H

50