4-nitrobenzyl (4R,5R,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-3,7-dioxo-1-azabicyclo[3.2.0]-heptane-2-carboxylate

L-羟基脯氨酸

Boc-L-羟脯氨酸

(2S,4S)-4-(乙酰基硫代)-2-(羟基甲基)-1-吡咯烷羧酸-1,1-二甲基乙酯

(2S,4R)-N-tetr-butoxycarbonyl-4-methanesulfonyloxy-2-hydroxymethylpyrrolidine