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

(3S,7aS)-methyl 3-tert-butyl-6-methyl-5-oxo-7-(trifluoromethylsulfonyloxy)-1,3,5,7a-tetrahydropyrrolo[1,2-c]oxazole-7a-carboxylate

methyl (R)-2-tert-butyloxazolidine-4-carboxylate