Stabilised 2, 3??Pyridyne Reactive Intermediates of Exceptional Dienophilicity

SJ Connon, AF Hegarty

Index: Connon, Stephen J.; Hegarty, Anthony F. European Journal of Organic Chemistry, 2004 , # 16 p. 3477 - 3483

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Citation Number: 23

Abstract

Abstract The enhanced dienophilicity of 4-methoxy, 4-aryloxy and 4-thiophenoxy analogues 6− 9 of 2, 3-pyridyne (2) relative to 2 itself is reported. The regioselective lithiation of 4- alkoxy-(22, 23 and 25) and 4-thiophenoxy-2-chloropyridine (24) at low temperatures, followed by elimination of lithium chloride affords 4-alkoxy-and 4-thiophenoxypyridynes, which can be trapped in situ in a [4+ 2] cycloaddition reaction with furan to give endoxides ...