Tetrahedron letters

Regioselective alkylation of substituted quinones by trialkylboranes

LW Bieber, PJR Neto, RM Generino

Index: Bieber, Lothar W.; Rolim Neto, Pedro J.; Generino, Regina M. Tetrahedron Letters, 1999 , vol. 40, # 24 p. 4473 - 4476

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Citation Number: 33

Abstract

2-Methoxy-1, 4-benzoquinone can be alkylated selectively with trialkylboranes in position 5, givinghigh yields of 5-alkyl-2-methoxy-1, 4-benzoquinones after oxidative work up. In the case of 2-hydroxy-1, 4-naphthoquinone, the same procedure leads to 3-alkylated products. A radical chain mechanism is proposed to explain the observed selectivity.