(3R,7aR)-methyl 3-tert-butyl-6-methy-5-oxo-7-(trifluoromethylsulfonyloxy)-1,3,5,7a-tetraydropyrrolo[1,2-c]oxazole-7a-carboxylate 、
3-溴丙烯 以97%的产率得到(3R,7aR)-methyl 7-(allyloxy)-3-tert-butyl-6-methy-5-oxo-1,3,5,7a-tetrahydropyrrolo[1,2-c]oxazole-7a-carboxylate