p-Toluenesulfonic acid → Ethyl {[5-(5-oxocyclopent-1-en-1-yl)pentyl]sulfanyl}acetate
Reaction equation
[C:1]([CH2:4][S:5][CH2:6][CH2:7][CH2:8][CH2:9][CH2:10][C:11]1[C:12](=[O:16])[CH2:13][CH2:14][CH:15]=1)([OH:3])=[O:2].[C:17]1(C)C=CC(S(O)(=O)=O)=C[CH:18]=1>C(O)C>[C:1]([CH2:4][S:5][CH2:6][CH2:7][CH2:8][CH2:9][CH2:10][C:11]1[C:12](=[O:16])[CH2:13][CH2:14][CH:15]=1)([O:3][CH2:17][CH3:18])=[O:2]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A mixture of 74 g. (0.306 mols) of 2-(7-carboxy-6-thiaheptyl)-2-cyclopentenone, 1200 ml. of ethanol and 1 g. p-toluenesulfonic acid is stirred and refluxed for 18 hours. The resulting solution is concentrated and the residue is dissolved in ether. The organic phase is washed with water, sodium bicarbonate solution and saline, dried (MgSO4) and evaporated. The residue is distilled to give a light yellow oil, o.p. 147°-150° C. (0.07 Torr).