Advices For Studying Organic Chemistry

H C

C

O H

C

O OH

C

O OH

C

O OH

C

O OH

OH

CH 2 OH

H C OH

CH 2 OH

HgO

(oxidation)

(+)-Glycealdehyde (−)-Glyceric acid

H C OH

CH 2

HNO 2

H 2 O

(+)-Isoserine

NH 2

HNO 2

HBr

H C OH

CH 2

(−)-3-Bromo-2-hydroxy-

propanoic acid

Br

Zn, H+ H

C OH

CH 3

(−)-Lactic acid

This bond

is broken

This bond

is broken

This bond

is broken

i) If the configuration of (+)-glyceraldehyde is as follows:

H C

C

O H

OH

CH 2 OH

(R)-(+)-Glycealdehyde

ii) Then the configuration of (–)-lactic acid is:

H C

C

O OH

OH

CH 3

(R)-(−)-Lactic acid

5. The configuration of (–)-glyceraldehyde was related through reactions of known
   stereochemistry to (+)-tartaric acid.