(2S,4S)-4-Acetylsulfanyl-2-{3-[(Z)-hydroxyimino]-pyrrolidine-1-carbonyl}-pyrrolidine-1-carboxylic acid allyl ester

(2S,4S)-2-{3-[(E)-Hydroxyimino]-pyrrolidine-1-carbonyl}-4-tritylsulfanyl-pyrrolidine-1-carboxylic acid allyl ester

(2S,4R)-4-Hydroxy-pyrrolidine-1,2-dicarboxylic acid 1-allyl ester 2-(4-methoxy-benzyl) ester

(2S,4S)-4-Acetylsulfanyl-pyrrolidine-1,2-dicarboxylic acid 1-allyl ester 2-(4-methoxy-benzyl) ester

(2S,4R)-4-Methanesulfonyloxy-pyrrolidine-1,2-dicarboxylic acid 1-allyl ester 2-(4-methoxy-benzyl) ester