Benzene → trans 2-(5-Cyano-3,4-dimethoxyphenyl)-4-(3,4,5-trimethoxyphenyl)-1,3-dithiolane

Participants

Reaction Steps

1-(3,4,5-trimethoxyphenyl)-1,2-ethanedithiol (2.36 g, 9.09 mmole), 5-cyano-3,4-dimethoxybenzaldehyde (49) (1.50 g, 7.85 mmole) and 0.788 g of pyridinium para-toluenesulfonate was added to 50 ml dry benzene and refluxed with Dean-Stark removal of the benzene-water azeotrope for 24 hours. The benzene was removed in vacuo, and the remaining oil redissolved in ethyl acetate. The organic layer was washed with 10% NaHCO3 and H2O. The organic layer was dried over MgSO4, and evaporated in vacuo to an oil which was purified by flash column chromatography with 2:1 hex/ethyl acetate as eluent. The product mixture contains a 1.0/1.0 cis/trans ratio (2.91 g, 86%).

Provenance & Evidence