Cyclization of 5-hexynoic acid to 3-alkoxy-2-cyclohexenones
The one-pot cyclization of 5-hexynoic acid to produce 3-alkoxy-2-cyclohexenones proceeds in good yields (58–90%). 3-Hexynoic acid was converted to its acyl chloride with the aid of oxalyl chloride and was cyclized to 3-chloro-2-cyclohexenone upon addition of indium(III) chloride. Subsequent addition of alcohol nucleophiles led to the desired 3-alkoxy-2-cyclohexenones.
Hylden, A. T.; Uzelac, E. J.; Ostojic, Z.; Wu, T-T; Sacry, K. L.; Sacry, K. L.; Xi, L.; Jones, T. N.* Cyclization of 5-hexynoic acid to 3-alkoxy-2-cyclohexenones. Beilstein J. Org. Chem., 2011, 7, 1323-1326.