tert-butyl (2R,3R,4R)-4-azido-3-tert-butyldimethylsilyloxy-2-hydroxymethylpyrrolidine-1-carboxylate

tert-butyl (2R,3S,4R)-4-tert-butoxycarboxamido-3-hydroxy-2-hydroxymethylpyrrolidine-1-carboxylate

tert-butyl (2R,3R,4S)-2-tert-butyldiphenylsilyloxymethyl-3,4-epoxypyrrolidine-1-carboxylate

tert-butyl (2R,3R,4R)-4-azido-2-tert-butyldiphenylsilyloxymethyl-3-hydroxy-pyrrolidine-1-carboxylate

(2R,3R,4R)-4-azido-3-tert-butyldimethylsilyloxy-1-tert-butoxycarbonyl-2-pyrrolidinecarboxylic acid