The syn the ses of methyl es ter of ( ±)-desepoxy-4,5-didehydromethylenomycin A ( 4) and 2,3-dimethyl-5methoxycarbonyl-2-cyclopentenone ( 5) were ac com plished from a com mon start ing ma te rial, 2,3-dimethyl4-methoxyphenol ( 8), in only four and two steps in 35% and 53% over all yields, re spec tively. Pho to chem i cal re ar range ments of masked p-benzoquinones in meth a nol are the key steps
(±)-去环氧-4,5-二去氢亚甲基霉素A(4)和2,3-二甲基-5甲氧羰基-
2-环戊烯酮(5)的甲酯的合成是由共同的起始材料完成的。材料,2,3-二甲基
4-甲氧基苯酚(8),仅经过四步和两步,总产率分别为35%和53%。甲基中掩蔽的
对苯醌的
化学反应是关键步骤。