(2S,3R,4E)-5-benzenesulfonyl-2,3-isopropylidenedioxy-pent-4-en-1-yl trifluoroacetate

(2S,3S,4E)-5-benzenesulfonyl-2,3-epoxy-pent-4-en-1-yl trifluoroacetate

(2R,3R,4S)-2-benzenesulfonylmethyl-3,4-isopropylidenedioxy-tetrahydrofuran

(R)-5-Oxo-1-((3aR,4R,7S,7aR)-2,2,7-trimethyl-tetrahydro-1,3,5-trioxa-6-aza-inden-4-yl)-pyrrolidine-2-carboxylic acid tert-butyl ester

(R)-5-Oxo-1-((3aR,4R,7aR)-2,2,7-trimethyl-3a,7a-dihydro-4H-1,3,5-trioxa-6-aza-inden-4-yl)-pyrrolidine-2-carboxylic acid tert-butyl ester