PIFA-mediated oxidative cycloisomerization of 2-propargyl-1, 3-dicarbonyl compounds: divergent synthesis of furfuryl alcohols and furfurals

A Saito, T Anzai, A Matsumoto, Y Hanzawa

Index: Saito, Akio; Anzai, Toshiyuki; Matsumoto, Asami; Hanzawa, Yuji Tetrahedron Letters, 2011 , vol. 52, # 36 p. 4658 - 4661

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Citation Number: 11

Abstract

PhI (OCOCF3) 2 (PIFA) in the presence of trifluoroacetic acid (TFA) in CH2Cl2 efficiently promotes the oxidative cycloisomerization of 2-propargyl 1, 3-dicarbonyl compounds to give 4, 5-disubstituted furfuryl alcohols. PIFA in hexafluoroisopropanol (HFIP) or PIFA-BF3· OEt2 in CH2Cl2 bring about the direct formation of furfurals from 2-propargyl 1, 3-dicarbonyl compounds. In a few cases, PhIO is suitable for the direct formation of furfurals.