Intramolecular diels-alder reaction with furan diene. A new synthesis of 11-keto steroids
作者:Luc A Van Royen、Roelant Mijngheer、Pierre J De Clercq
DOI:10.1016/s0040-4039(00)88118-6
日期:1983.1
furan-diene in water as a key-step. The dienophilic side chain is readily introduced starting from via a sequence involving alkylation with ethyl 4-iodo-3-ethoxycrotonate, reduction and acid hydrolysis. The reduced adduct , obtained in 24 % overall yield from 2-methyl-1,3-cyclocpentanedione, is converted into (±)-adrenosterone ( via base-opening to and further transformation to , the dienediolate equivalent
据报道,一条新的D→BCD→ABCD途径可合成11-酮类固醇,其中关键步骤是高产率的呋喃二烯在水中的立体选择性分子内Diels-Alder反应。亲二烯键侧链容易地通过涉及与4-碘-3-乙氧基巴豆酸乙酯的烷基化,还原和酸水解的顺序开始引入。从2-甲基-1,3-环戊烷二酮以24%的总收率获得的还原的加合物被转化为(±)-肾上腺素(通过将其开环并进一步转化为,其二烯二醇酯当量是已知的中间体)。皮质类固醇合成。