Cycloaddition of Cross-Conjugated Trienes to Halogenated Quinones
作者:Michel Couturier、Paul Brassard
DOI:10.1055/s-1994-25553
日期:——
The chemoselectivity of [4 + 2] cycloadditions involving electronrich cross-conjugated trienes and halogenated quinones has been examined. The approach provides improved preparations of 6-acetyl-2,3,7-trihydroxyjuglone, solorinic and norsolorinic acids, and averythrin. It also confirms the structure proposed for haematommone and 3,8-dihydroxy-4-methoxy-2-methoxycarbonyl-1-methyl-anthraquinone but invalidates that of sopheranin.