Résumé/Abstract A synthesis of the new heterocycles, 4-methyl-2H-pyrano [6, 5-f] cycloalka [2, 1-b] 2H-chromen-2-ones (3) was described, via the unexpected intermediates 2-chloro-1- chloroethenylidenecycloalkanes (6) from the reaction of 1-ethynylcycloalkanols with thionyl chloride. The mechanism of some steps was discussed.
