Abstract
The hitherto unreported title compounds were obtained in good yields by the application of [3,3]sigmatropic rearrangement on 4-]2′-propynyloxy] [1]benzothiapyran-2-one and 4-[2′-propenyloxy][1]benzothiapyran-2-one or 4-[2′-chloro-2′-propenyloxy][1]benzothiapyran-2-one respectively.