Regioselective Synthesis of 3‐(Aryloxyacetyl)‐2,3‐dihydrothieno[2,3‐b][1]benzothiopyran‐4‐ones via Tandem Cyclization
摘要:
2-[4-Aryloxybut-2-ynylthio][1]benzothiopyran-4-ones on treatment with m-chloroperoxy benzoic acid in chloroform at 0degreesC to room temperature afforded 3-(aryloxyacetyl)-2,3-dihydrothieno[2,3-b]benzothiopyrans in 65-70% yield. The sigmatropic [2,3] followed by [3,3] rearrangement, are attributed to this transformation.