A NOVEL SYNTHETIC APPROACH TO MEDIUM RING LACTONES VIA DIENETRICARBONYLIRON COMPLEXES

Reaction of lithium diisopropylamide (LDA) with (eta(4)-1,3-buadiene)F e(CO)(3) complexes bearing carboester functionalized side chains at C- 5 gives eight- to ten-membered lactones as the major products after el ectrophilic quenching. However, treatments of the complexes with LDA, under an atmosphere of carbon monoxide, furnish bridged bicyclo[5.2.1] decane and bicyclo[6.2.1]undecane lactone skeletons as the major produ cts. Copyright (C) 1996 Elsevier Science Ltd