Benzene → trans 2-(4-Hydroxy-5-iodo-3-methoxyphenyl)-4-(3,4,5-trimethoxyphenyl)-1,3-dithiolane
Reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:13]2[CH2:17][S:16][C:15](=S)[S:14]2)[CH:6]=[C:7]([O:11][CH3:12])[C:8]=1[O:9][CH3:10].[I:19][C:20]1[C:21]([OH:30])=[C:22]([O:28][CH3:29])[CH:23]=[C:24]([CH:27]=1)C=O.C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1.C1C=CC=CC=1>C1C=CC=CC=1.O>[OH:30][C:21]1[C:20]([I:19])=[CH:27][C:24]([C@H:15]2[S:14][C@H:13]([C:5]3[CH:6]=[C:7]([O:11][CH3:12])[C:8]([O:9][CH3:10])=[C:3]([O:2][CH3:1])[CH:4]=3)[CH2:17][S:16]2)=[CH:23][C:22]=1[O:28][CH3:29]Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Procedure
1-(3,4,5-trimethoxyphenyl)-1,2-ethanedithiol (32) (FIG. 26) (0.500 g, 1.92 mmole), 5-iodovanillin (0.411 g, 1.48 mmole), pyridinium para-toluenesulfonate (0.193 g, 0.769 mmole) and 50 ml dry benzene were refluxed under an argon atmosphere with Dean-Stark removal of the benzene-water azeotrope for 12 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 1.0/1.3 cis/trans ratio (0.578 g, 75%) after one crystallization from methanol. The trans isomer (50 mg) was isolated after one additional crytallization from ethanol.
Workup
- customThe benzene was removed in vacuo
- dissolutionthe remaining oil redissolved in dichloromethane
- washThe organic layer was washed with 3×30 ml H2O
- dry with materialwas dried over MgSO4
- customevaporated in vacuo to an oil which
- customwas purified by flash column chromatography with 2:1 hex/ethyl acetate as eluent
- customafter one crystallization from methanol
- customThe trans isomer (50 mg) was isolated after one additional crytallization from ethanol
Sources & evidence
- ORD record
- ord-fd78168f65a14c9aa3b76e50648110a3
- Source dataset
- uspto-grants-1997_06
- Patent number
- US05639782
Reaction notes
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