Bu 3 SnH mediated oxidative radical cyclisations: synthesis of 6 H-benzo [c] chromen-6-ones

WR Bowman, E Mann, J Parr

Index: Bowman, Russell; Mann, Emma; Parr, Jonathan Journal of the Chemical Society, Perkin Transactions 1, 2000 , # 17 p. 2991 - 2999

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Citation Number: 68

Abstract

Attempts to synthesise 6H-benzo [c] chromen-6-ones by Bu3SnH mediated cyclisation of o- (benzoyl) aryl radicals failed because of the preferred trans conformation of the ester. This problem was overcome by using cyclisation of o-(benzyloxy) aryl and o-[(aryloxy) methyl] aryl radicals to yield 6H-benzo [c] chromenes followed by oxidation to the 6H-benzo [c] chromen-6-ones. 3-Methoxy-6H-benzo [c] chromen-6-one 1, one of the main biologically ...