(Alkoxyallyl)sulfones as enal and enone β-anion equivalents. Synthesis of mono-, di- and trisubtituted furans
摘要:
Treatment of variously-substituted (alkoxyallyl)sulfones 1, 7-9 with strong base followed by aldehydes gives alcohol adducts 5. These may be converted into a wide range of substituted furans 6 by exposure to acid, or to silica gel in dichloromethane containing sulfuric acid in some cases. Copyright (C) 1996 Elsevier Science Ltd
A procedure is described for the synthesis of furans from 3-alkyn-1,2-diols or 2-methoxy-3-alkyn-1-ols by palladium catalyzed intramolecular addition of alcoholic moiety to acetylene linkage followed by elimination of water or methanol. The intermediary 3-furylpalladiums can be trapped with allyl halides affording 3-allylfurans in good yields.