trans-(1R,2R)-2-tert-butoxycarbonylaminocyclopentanecarboxylic acid ethyl ester

(-)-环戊酮-反式-3,4-二羧酸二甲酯

trans-(7R,8R)-1,4-dithiaspiro[4.4]nonane-7-carboxylic acid-8-carboxylic acid methyl ester

(-)-trans-(7R,8R)-1,4-dithiaspiro[4.4]nonane-7,8-dicarboxylic acid dimethyl ester

N-(tert-butyloxycarbonyl)-trans-(7R,8R)-1,4-dithiaspiro[4.4]nonane-7-amino-8-carboxylic acid methyl ester