Synthesis and Base-Induced Methylation Reactions of cis-7a-Hydroxy-3a-(phenylsulfenyl)-3a,4,5,6,7,7a-hexahydro-4-indanone

Article abstract of DOI:10.1021/jo00383a020

cis-7a-Hydroxy-3a-(phenylsulfenyl)-3a,4,5,6,7.7a-hexahydro-4-indanone (2) was prepared by reaction of 10-oxatricyclo<4.3.1.0>decan-2-one with sodium thiophenoxide in THF.Reaction of 2 with potassium hydride in THF/HMPA and an excess of a methylating agent gave cis-7a-methoxy-3a-(phenylsulfenyl)-3a,4,5,6,7,7a-hexahydro-4-indanone (8) and 1-methyl-7-(phenylsulfenyl)bicyclo<4.3.0>-6(7)-nonen-2-one (9), which apparently arose by a retroaldol reaction followed by recyclization, formation of dienolate, and C-alkylation.The ratio of 8 and 9 was dependent upon the reaction con ditions.When DME rather than THF was used as a solvent in some runs, 2 apparently underwent a 1,3-sigmatropic rearrangement of the phenylsulfenyl group because 3-(phenylsulfenyl)bicyclo<4.3.0>-1(6)-nonen-2-one (14) and its C-3 methylation product 15 were isolated.