Substituted 3, 4-pyridynes: clean cycloadditions

SJ Connon, AF Hegarty

Index: Connon, Stephen J.; Hegarty, Anthony F. Journal of the Chemical Society, Perkin Transactions 1, 2000 , # 8 p. 1245 - 1249

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Citation Number: 23

Abstract

The stabilisation of 3, 4-pyridyne (1) by an alkoxy group adjacent to the ring nitrogen is reported. The regioselective lithiation of 2-ethoxy-(14), 2-methoxy-(18), 2-isopropoxy-(19) and 6-isopropoxy-(26)-3-chloropyridines with tert-butyllithium at low temperatures, followed by elimination of lithium chloride affords 2-and 6-alkoxy-3, 4-pyridynes. These species are trapped in situ with furan in a Diels–Alder reaction to give 5–8 in 66–89% yield, and do not ...