Partial synthesis of 6β-eudesmanolides and 6β-guaianolides from 6α-eudesmanolides: Synthesis of analogues of artepaulin, colartin and tannunolide D
作者:José L. Bretón、Juan J. Cejudo、Andrés García-Granados、Andrés Parra、Francisco Rivas
DOI:10.1016/s0040-4020(01)87003-4
日期:1994.2
The epimerization process consists of the LiA1H4 reduction of a 6α-lactone, selective protection of the hydroxymethylene group at C-12, oxidation and reduction at C-6 to epimerize this carbon, deprotection at C-12 and finally, lactonization with tetrapropylammonium perruthenate (TPAP) and 4-methylmorpholine N-oxide (NMO) in yields over 80%. The rearrangement of 1β-hydroxy-6β-colartin allow us to obtain
通过化学方法实现多官能化的6α-马来酸酐在C-6的差向异构化,以获得6β-马来酸酐,并且在重排后获得6β-愈创木酚内酯。差向异构化过程包括LiA1H 4还原6α-内酯,对C-12处的羟甲基进行选择性保护,在C-6处进行氧化和还原以使该碳异构化,在C-12处进行脱保护,最后用四丙基过钌酸内酯进行内酯化(TPAP)和4-甲基吗啉N-氧化物(NMO),收率超过80%。1β-羟基-6β-colartin的重排使我们可以获得2,3-二氢-6β-鞣酸内酯D.