p. 2539 - 2543
(1986)p. 745 - 753
(1994)p. 1145 - 1147
(2007/10/03)methyl N-tert-butyloxycarbonyl-L-azetidine-2-carboxylate
acetaldehyde
(3S,4R)-3-(trimethylsilyl)-2-oxoazetidine-4-carboxylic acid methyl ester
methanol
(S)-benzyl 4-oxoazetidine-2-carboxylate