Bicyclo[3.4.0]non-1-en-derivate. synthese von des-a-pregn-9-en-3,20-dion
作者:E.-J. Brunke、H. Bielstein、R. Kutschan、G. Rehme、H.-J. Schuetz、H. Wolf
DOI:10.1016/0040-4020(79)80023-x
日期:1979.1
Cyclization of the allylic alcohols 12,17 and 22 easily obtainable from Hagemann's ester (2 or 1) via the cyclohexenone derivatives 7 and 10 was investigated with regard to steroid syntheses of the pregnane series. The 6,7-cis-tetrahydroindane derivatives 16a and 23 are formed stereoselectively by acid catalyzed cyclization of 12 or 22; ring closure of 22 occurs largely regioselectively. Cyclization
烯丙基醇的环化12,17和22从哈格曼的酯(容易得到的2或1经由环己烯酮衍生物)7和10相对于孕系列的类固醇的合成进行了研究。6,7-顺式-四氢茚满衍生物16a和23通过酸催化环化12或22选择性地形成。22的闭环在很大程度上区域选择性地发生。17的环化选择性产生6,7-顺式(18a)或6,7-反式化合物(18b)。通过23的烯丙基氧化,随后的氢化和醛醇缩合获得Des-A-pregn-9-en-3,20-dion(28a)。