(3aS,6R,7R,7aR)-1-methyl-6-(2-oxopropyl)-7-(triethylsilyloxy)hexahydropyrano[4,3-d]oxazol-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,5aR,8aR,8bS)-1-aza-1-methyl-3,5,8-trioxa-as-hexahydroindacene-2,7-dione

(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