Studies on the Synthesis of Natural Products with Bicyclo[4.4.0]decene Skeleton: Synthesis and Uncatalysed Intramolecular Diels–Alder Reactions of the Decatrienone Substrates
作者:Barbara Frey、Jürgen Schnaubelt、Hans-Ulrich Reißig
DOI:10.1002/(sici)1099-0690(199906)1999:6<1377::aid-ejoc1377>3.0.co;2-l
日期:1999.6
synthesized. Cyclopropanation and subsequent alkylation with sorbyl bromide provided tetrasubstituted siloxycyclopropanes 15 and 16 in good overall efficiency. Their ring cleavage with fluoride reagents gave 1,7,9-decatrienones 5 and 17; the latter was converted into the protected compound 6. The thermal intramolecular Diels–Alder reactions of 5 and 6 were compared with those of related trienones 3 and
以烯酮 7 和 8 为原料合成了甲硅烷氧基二烯 9 和 12。环丙烷化和随后用山梨基溴进行烷基化以良好的整体效率提供四取代的甲硅烷氧基环丙烷 15 和 16。它们用氟化物试剂进行环裂解得到 1,7,9-癸三烯酮 5 和 17;后者转化为受保护的化合物 6。将 5 和 6 的分子内 Diels-Alder 热反应与相关的三烯酮 3 和 4 的热分子内反应进行比较。八酮 1、2、21 和 22 作为三种或四种非对映体的混合物形成. 因此,对于天然产物的立体选择性构建,例如 α-eudesmol 或 dihydromevinolin,必须开发用于环加成步骤的替代反应条件。