(-)-(3aR,5S,7aR)-(2-phenyl-5,7a-dihydro-3aH-pyrano[3,2-d][1,3]oxazol-5-yl)methyl acetate 、
(-)-(1S,2R,3S,7S,8R)-4,4-dimethyl-3-nitro-9,11-dioxatricyclo[6.2.1.0(2,6)]undec-5-en-7-ol 在
氢溴酸 作用下,
以
1,2-二氯乙烷 为溶剂,
以38%的产率得到(-)-(1'S,4'R,5'S,8'S,8a'R)-(7,7-dimethyl-8-nitro-1,4,5,7,8,8a-hexahydro-2H-1,4-epoxycyclopenta[d]oxepin-5-yl) 6-O-acetyl-2-benzamido-2,3,4-trideoxyhex-3-enopyranoside