Cyclization of Aryllithiums Tethered to Methylenecycloalkanes: Stereoselective Synthesis of 4 a-Substituted cis-Hexahydrofluorenes

WF Bailey, T Daskapan, S Rampalli

Index: Bailey, William F.; Daskapan, Tahir; Rampalli, Sriram Journal of Organic Chemistry, 2003 , vol. 68, # 4 p. 1334 - 1338

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Citation Number: 34

Abstract

The cyclization of an aryllithium tethered to a methylenecycloalkane, generated from 2-(o- bromobenzyl)-1-methylenecycloalkanes 1, 2, and 3 by low-temperature lithium-bromine exchange, has been found to be a kinetically slow but thermodynamically favorable process that proceeds at a convenient rate in an exclusively 5-exo fashion when solutions of the aryllithium in n-heptane-di-n-butyl ether (9: 1 v/v) are warmed to 45° C. The cyclization ...