3. (25 pts total) Stereochemistry (a) (10 pts total) Indicate the category (constitutional, conformational, enantiomer or diastereomer) of the following isomer pairs: CHO CHO H- OH H CH3 HO H HO H HC H3C H OH HO H H2C OH NH2 Leucine OH NH2 Isoleucine H OH H OH CH OH 2 D-glucose D-galactose (1) (Fisher projection) (ii) (Dash-Wedge projection) Answer: Answer: H CH H NH2 H2N- -C -COOH H2N- -COOH H2N- -COOH H-C COOH . H CH3 (ii) (Fisher projection) Answer: (iv) (Fisher projection) Answer: (b) (15 pts total) Indicate the R/S configuration of all the chiral centers of (1) and (2) and the Z/E configuration of the double bond in (3): H H CHE OH H Ilm H 3 OH H 5 2 (1) (2) H H OH CI (3) ON Page 5 of 5