An eficient catalytic enantiosekctive synthesis of the important antidepressant sertmhe is described (Scheme Z). (+)-cis-( 1S,4S)-1-Methylamino-4-(3,4-dichlorophenyl)tetralin, sertraline (Zoloft@) (1). is a major commercial phsrmace utical agent for the treatment of depression, acting in the central nervous system as a serotonin uptake inhibitor.12 The current commercial process for the production of sertraline involves the synthesis of (f)-1 followed by resolution. 3 At present only one enantioselective synthesis of 1 has been mporkd, the key steps of which am ' ed below? 2 0 0 % --t' '" 0 Cl CI In this synthesis, chirality is introduced by means of the oxaxaborolidine-catalyxed (CBS) reduction of ketone 2 which affords product of 90% ee. The penultimate intermediate, k&alone 3 was obtained in 86% enantiomeric Described herein is a different approach to the synthesis of sertraline which involves catalytic asymmetric synthesis and which produces tetralone 3 of 100% cc in excellent yield. The reaction scqucnce is summarixcd in scheme I. Reaction of methyl (E)-2-diazo-+phenyl-3-butenoa& (4) with 3.3 equiv of styrene and 0.1 mole % of catalyst 55 in pentane solution at 0 "C for 18 h afforded cyclopropane 65 in 94% ee and 79% yield. Remystallization of this product from hexane gave enantiomerically pure 6 (85% recovery), mp 77-78 T, [a]g