ONE-POT SYNTHESIS OF HIGHLY SUBSTITUTED CYCLOPENTANOLS VIA TITANAHETEROCYCLES - STEREOSELECTIVE COUPLING REACTIONS OF ALPHA,BETA-UNSATURATED ARYLKETONES

A novel synthesis of highly substituted 1,3,4-triaryl-2-aroyl-cyclopen tanols 1 from unsaturated arylketones 2 and dicarbonyl titanocene 3 vi a stereoselective twofold C-C-coupling reactions has been developed. T he hitherto unknown 2,9-dioxa-titanacyclononadiene complexes 4, well d efined products of the initial trans-selective beta,beta-coupling reac tion, can optionally be isolated or hydrolyzed to give 1. The mild and non-hazardous reaction conditions give high yields of 1 as the sole p roduct in most cases. Occasionally only aroyl-cyclopentenes 5 could be found due to a swift follow-up dehydration process.