Abstract
Although 1-ethynyl-2-allenylbenzenes readily undergo Myers-Saito or Schmittel cyclization under mild conditions, cyclocarbonylation of these moieties to 1H-cyclopenta[a]inden-2-ones proceeds smoothly using suitable molybdenum carbonyl reagents, with Mo(CO) 3 (CH 3 CN) 3 being the most efficient. The yields of desired bicyclic ketones were up to 87-93%. © 2005 Elsevier Ltd. All rights reserved.