Investigation of unsaturated lactones

Transesterification with subsequent cyclization to 4-carbethoxy-5,6,6-trialkyl-3-hydro-2-pyrones occurs during condensation of -keto alcohols with diethyl succinate. 4-Carbethoxy-5,6,6-trimethyl-3-hydro-2-pyrone was obtained by reaction of dimethylethynylcarbinol with the ethyl ester of succinic acid monochloride and subsequent hydration of the acetylenic ester and cyclization.See 1] for communication XXIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1604–1607, December, 1973.