(4S,5S,1'S,E)-4-[4'-benzyloxy-1'-(tert-butyldimethylsilyloxy)but-2'-enyl]-5-(benzyloxy)methyl-3-methyloxazolidin-2-one

methyl (2S,3a'S,6'R,7'R,7a'S)-2-methoxycarbonylamino-4[[1'-methyl-2'-oxo-7'-(triethylsilyloxy)hexahydropyrano[4,3-d]oxazol-6'-yl]methyl]pent-4-enoate

(3aS,6R,7R,7aR)-1-methyl-6-(2-oxopropyl)-7-(triethylsilyloxy)hexahydropyrano[4,3-d]oxazol-2-one

methyl (2S,4R,3a'S,6'R,7'R,7a'S)-4,5-epoxy-2-methoxycarbonylamino-4-[[1'-methyl-2'-oxo-7'-(triethylsilyloxy)hexahydropyrano[4,3-d]oxazol-6'-yl]methyl]pentanoate

(3aS,6R,7R,7aR)-1-methyl-7-triethylsilyloxy-6-[(2-trifluoromethanesulfonyloxy)prop-2-enyl]hexahydropyrano[4,3-d]oxazol-2-one

(S)-4-((3aS,6R,7R,7aS)-7-Hydroxy-1-methyl-2-oxo-hexahydro-pyrano[4,3-d]oxazol-6-ylmethyl)-2-methoxycarbonylamino-pent-4-enoic acid methyl ester

(3a'S,6'R,7'R,7a'S)-N-methoxy-N-methyl-2-[1'-methyl-2'-oxo-7'-(triethylsilyloxy)hexahydropyrano[4,3-d]oxazol-6'-yl]acetamide

(3aS,5aR,8aR,8bS)-1-aza-1-methyl-3,5,8-trioxa-as-hexahydroindacene-2,7-dione