Stereoselective Introduction of Oxygen Functionalities at the 11.BETA.-Position of Erythrinan Skeleton: Total Syntheses of (.+-.)-Erythristemine and (+)-Erythrartine.
作者:Kimiaki ISOBE、Kunihiko MOHRI、Naoko TAKEDA、Kazumi SUZUKI、Shinzo HOSOI、Yoshisuke TSUDA
DOI:10.1248/cpb.42.197
日期:——
Oxidation of 8-oxoerythrinan and 8-oxo-1, 7-cycloerythrinan derivatives with 2 mol eq of ceric ammonium nitrate in alcohols or acetic acid gave the corresponding 11β-alkoxy or acetoxy compounds in moderate yield. Thus, (±)-3, 3, 15, 16-tetramethoxy-1, 7-cycloerythrinan-2, 8-dione and (+)-erysotramidine gave the corresoponding 11β-methoxy and 11β-acetoxy derivatives on oxidation in methanol and in acetic acid, respectively. Those compounds were respectively converted into (±)-erythristemine and (+)-erythrartine in several steps, thus achieving the total synthesis of these alkaloids.
在醇或乙酸中,使用2摩尔当量的硝酸铈铵对8-氧代赤藓烷和8-氧代-1,7-环赤藓烷衍生物进行氧化反应,以中等产率得到了相应的11β-烷氧基或乙酸氧基化合物。因此,(±)-3,3,15,16-四甲氧基-1,7-环赤藓烷-2,8-二酮和(+)-赤藓酰胺分别在甲醇和乙酸中氧化,得到了相应的11β-甲氧基和11β-乙酸氧基衍生物。这些化合物分别经过几步反应,转化为(±)-赤藓碱和(+)-赤藓石碱,从而实现了这些生物碱的全合成。