p-Toluenesulfonic acid → 3-[(Butylsulfanyl)methylidene]oxolan-2-one
Reaction equation
CN([CH:4]=[C:5]1[CH2:9][CH2:8][O:7][C:6]1=[O:10])C.[CH2:11]([SH:15])[CH2:12][CH2:13][CH3:14].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1C=CC=CC=1>[CH2:11]([S:15][CH:4]=[C:5]1[CH2:9][CH2:8][O:7][C:6]1=[O:10])[CH2:12][CH2:13][CH3:14]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
A mixture of γ-butyrolactone (1 mol) and tris(dimethylamino)methane (1.5 mol) is stirred under dry nitrogen at 75° C. for 2 days to give 3-[(dimethylamino)methylene]dihydro-2(3H)-furanone. A solution containing 3-[(dimethylamino)methylene]dihydro-2(3H)-furanone (1 mol), n-butanethiol (1.1 mol) and para-toluenesulfonic acid (1 mol) in benzene is heated at reflux overnight to give upon aqueous work-up 3-[(butylthio)methylene]dihydro-2(3H)-furanone. After a solution of 3-[(butylthio)methylene]dihydro-2(3H)-furanone (1 mol) in anhydrous diethyl ether is added to a solution of lithium di-n-butylcuprate (1.1 mol) in diethyl ether at -78° C., the resulting mixture is stirred at -78° C. for an additional 0.5 hours and then quenched with methanol. Work-up affords 3-ethylidenedihydro-2(3H)-furanone. Freshly prepared W-2 Raney nickel (about 3 parts) is deactivated by refluxing in benzene for 1 hour, whereupon 3-ethylidenedihydro-2(3H)-furanone is added and the mixture is heated at reflux under nitrogen for 24-48 hours; the reaction is monitored by thin layer chromatography. After complete washing of the Raney nickel with hot benzene, the title compound is obtained.
Workup
- temperatureis heated
- temperatureat reflux overnight
Sources & evidence
- ORD record
- ord-baf41da3cff24887bb21ecdc18ab511c
- Source dataset
- uspto-grants-1991_11
- Patent number
- US05066663
Reaction notes
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