(3R,4R)-benzyl 3-(tert-butoxycarbonylamino)-4-(methylsulfonyloxy)-piperidine-1-carboxylate

benzyl (3aR,7aS)-2-oxohexahydro[1,3]oxazolo[4,5-c]pyridine-5(4H)-carboxylate

(3aR,7aS)-5-benzyl 3-tert-butyl 2-oxo-tetrahydrooxazolo[4,5-c]pyridine-3,5(2H,6H)-dicarboxylate

tert-butyl (3aR,7aS)-5-(6-nitrothieno[3,2-b]pyridin-7-yl)-2-oxohexahydrooxazolo[4,5-c]pyridine-3(2H)-carboxylate