Advices For Studying Organic Chemistry

(R)-Lactic acid

CH 3 (S)-Lactic acid

OH

H

HOOC

Same as

90 o rotation

COOH HOH CH 3

C

COOH H OH CH 3

C

OH HOOC CH 3 H

One group hold steady and the other three can rotate:

Hold steady COOH HOH CH 3

COOH HO CH 3 H

Same as

Differentiate different Fischer projections:

OH

H 3 C CH 2 CH 3

H

CH 3

HO H

CH 2 CH 3

H CH 3

OH

ABC

CH 3

HO H

CH 2 CH 3

B

H CH 3

OH CH 2 CH 3 OH

H 3 C CH 2 CH 3

H

A

Hold CH 3 Hold CH 2 CH 3 Rotate other three groups clockwise

Rotate other three groups clockwise