STEREOSPECIFIC HYDROGENATIONS .3. PALLADIUM-ON-POLY-GAMMA-BENZYL-S-GLUTAMATE AND PALLADIUM-ON-POLY-BETA-BENZYL-S-ASPARTATE

Stereospecific hydrogenations were demonstrated using palladium‐on‐poly‐γ‐benzyl‐S‐glutamate and palladium‐on‐poly‐β‐benzyl‐S‐aspartate. The results of the hydrogenation experiments indicate that the helical conformations of the poly‐S‐amino acid carriers influence the asymmetric induction observed. Hydrogenations using palladium‐on‐poly‐γ‐benzyl‐S‐glutamate produced R(–) ‐dihydro‐α‐methylcinnamic acid and S(–)‐phenylalanine (after hydrolysis of the hydrogenation product) when α‐ methylcinnamic acid and α‐acetamidocinnamic acid, respectively, were used as substrates. When hydrogenations were carried out using palladium‐on‐poly‐β‐benzyl‐S‐aspartate as the catalyst and the same substrates, S(+)‐dihydro‐α‐methylcinnamic acid or R(+)‐phenylalanine (after hydrolysis of the hydrogenation product were produced). Copyright © 1969 Wiley‐Liss, Inc., A Wiley Company