Stereoselective reactions. VIII. Stereochemical requirement for the benzylic oxidation of lignan lactone. A highly selective synthesis of the antitumor lignan lactone steganacin by the oxidation of stegane.
作者:TSUNEO ISHIGURO、HIDEMICHI MIZUGUCHI、KIYOSHI TOMIOKA、KENJI KOGA
DOI:10.1248/cpb.33.609
日期:——
A highly efficient synthesis of the antitumor steganin lignan steganacin (1) was accomplished. Bromination of stegane (7) with N-bromosuccinimide followed by treatment with aqueous tetrahydrofuran afforded steganol (3) in 85% yield. Acetylation of 3 gave 1 in 72% yield. Stegane (7) was also oxidized with 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone in AcOH to give 1 directly in 10% yield. Stereochemical requirements for the benzylic oxidation of dibenzocyclooctadiene lignan lactones are discussed.
我们完成了抗肿瘤甜菜苷木质素甜菜苷(1)的高效合成。用 N-溴代丁二酰亚胺溴化 stegane (7),然后用四氢呋喃水溶液处理,可得到 steganol (3),收率为 85%。对 3 进行乙酰化后得到 1,收率为 72%。Stegane (7) 也在 AcOH 中与 2,3-二氯-5,6-二氰基-1,4-苯醌发生氧化反应,直接得到 1,收率为 10%。讨论了二苯并环辛二烯木质素内酯苄基氧化的立体化学要求。