Vinylic cations from solvolysis. 39. Solvolysis of 9-[. alpha.-bromo-and. alpha.-(tosyloxy)-p-methoxybenzylidene] xanthenes

Z Rappoport, J Kaspi, D Tsidoni

Index: Rappoport, Zvi; Kaspi, Joseph; Tsidoni, Dov Journal of Organic Chemistry, 1984 , vol. 49, p. 80 - 84

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Citation Number: 5

Abstract

Results Synthesis. 9-(p-Methoxybenzylidene) xanthene was prepared by addition of (p- methoxybenzy1) magnesium chloride to xanthone in a modification of Van Campen's method, which reduces the extent of dimerization of the Grignard reagent.'O Addition of bromine to the alkene proceeded slowly and was accompanied by evolution of HBr and the formation of 5. Both the slow addition and the elimination of HBr are ascribed to steric ...