On the Carbocyclization of omega-styrenylbenzyllithiums

omega-Styrenylbenzyllithiums readily available from the corresponding omega -styrenylbenzyl selenides and butyllithiums provide after methanolysis 1-ar yl-2-benzyl cyclopentanes with very high stereocontrol. The compound bearin g these two groups in tl ans-position is produced, when the reaction is car ried out in THF at -78 degrees C or in ether at -100 degrees C whereas its stereoisomer is generated if the reaction is performed in ether at 0 degree s C. We proved that these reactions occur under kinetic control.