(4S)-4-benzyloxycarbonylamino-6',7'-epoxy-1',3,4,4',4'a,8'a-hexahydrospiro[furan-2(5H),5'(8'H)-1',4'-methanonaphthalene]-5',8'-dione

benzyl ((1'S,2S,4S,4'R,4a'S,6'S,8a'R)-6'-hydroxy-5,8'-dioxo-4,4',4a',5,6',7',8',8a'-octahydro-1'H,3H-spiro[furan-2,5'-[1,4]methanonaphthalen]-4-yl)carbamate

(1S,4R,4'S,4aS,5S,6S,8aR)-4'-benzyloxycarbonylamino-6-triethylsilyloxy-1,3',4',4,4a,6,7,8a-octahydrospiro[furan-2'(5H),5(8H)-1,4-methanonaphthalene]-5',8-dione