反应详情

1-(3,4,5-trimethoxyphenyl)-1,2-ethanedithiol (39) (0.148 g,0.57 mmole), 3,5-dimethoxy-4-methylthiobenzaldehyde (48) (FIG. 23) (0.11 g, 0.519 mmole) and 0.052 g of pyridinium para-toluenesulfonate was added to 40 ml dry benzene and refluxed with Dean-Stark removal of the benzene- water azeotrope for 48 hours. The benzene was removed in vacuo, and the remaining oil redissolved in dichloromethane. The organic layer was washed with 3×30 ml H2O and 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 (0.151 g, 64%). The trans isomer was isolated after two recrytallizations of this mixture from methanol.

1. customThe benzene was removed in vacuo
2. dissolutionthe remaining oil redissolved in dichloromethane
3. washThe organic layer was washed with 3×30 ml H2O
4. dry with materialwas dried over MgSO4
5. customevaporated in vacuo to an oil which
6. customwas purified by flash column chromatography with 2:1 hex/ethyl acetate as eluent
7. customThe trans isomer was isolated after two recrytallizations of this mixture from methanol