Synthesis of anisomycin. Part I. The stereospecific synthesis of N-benzoyl-2-(p-methoxybenzyl)-3-hydroxy-4-carboxamido pyrrolidine and the absolute configuration of anisomycin
L-Tyrosine was converted sterospecifically to N-benzoyl-2-(p-methoxybenzyl)-3-hydroxy-4-cyanopyrrolidine (10) which had a specific optical rotation [[alpha]][image] +9.7[degree]. Anisomycin was converted also to N-benzoyl-2-(p-methoxybenzyll-3-hydroxy-4-cyanopyrrolidine (16) which had a specific rotation [[alpha]]o -11[degree]. The infrared spectra of the synthetic compound and the derivative of anisomycin were superim- posable with each other. The absolute configuration of the 3 asymmetric center in (10) of synthetic origin were 2S, 3S, 4S, and those in (16) were 2R, 3R, 4R. Thus, anisomycin should have the absolute stereochemistry 2R, 3S, 4S as depicted in the structure (2). Hydrolysis of the hydroxy nitriles (8) and (10) gave an identical amide (3) which should have the absolute stereochemistry 2S, 3S, 4R as shown in structure (3).