(1S,5R,6S)-7-(diethoxy-phosphoryl)-5-methanesulfonyloxy-7-aza-bicyclo[4.1.0]hept-2-ene-3-carboxylic acid ethyl ester

(3R,4S,5R)-4-amino-3-(1-ethyl-propoxy)-5-methanesulfonyloxy-cyclohex-1-enecarboxylic acid ethyl ester

ethyl 3,4-O-isopropylidene-5-O-methanesulfonyl quinate

ethyl 3,4-O-isopropylidene-5-O-(methansulfonyl)shikimate

ethyl (3aR,7R,7aR)-2,2-dimethyl-7-methanesulfonyloxy-3a,6,7,7a-tetrahydrobenzo[1,3]dioxole-5-carboxylate