(3S,7aR)-methyl 7-((3R,4R,1E)-5-(benzyloxy)-4-hydroxy-3-methylpent-1-enyl)-3-tert-butyl-6-methyl-5-oxo-1,3,5,7a-tetrahydropyrrolo[1,2-c]oxazole-7a-carboxylate

(3S,6S,7aR,E)-methyl 7-((3R,4R)-5-(benzyloxy)-4-(tert-butyldimethylsilyloxy)-3-methylpentylidene)-3-tert-butyl-6-methyl-5-oxohexahydropyrrolo[1,2-c]oxazole-7a-carboxylate

(3S,6R,7aR,E)-methyl 7-((3R,4R)-5-(benzyloxy)-4-(tert-butyldimethylsilyloxy)-3-methylpentylidene)-3-tert-butyl-6-methyl-5-oxohexahydropyrrolo[1,2-c]oxazole-7a-carboxylate