Synthesis of Highly Functionalized Pentalenes via Intermolecular Pauson—Khand Reaction.

Abstract

Cyclopentane derivatives Q 0030Synthesis of Highly Functionalized Pentalenes via Intermolecular Pauson-Khand Reaction. -On treatment with diorganocuprates, Pauson-Khand cyclization products (I) give the corresponding 2,3-trans-disubstituted products which are transformed to diols via ozonolysis and reduction of the intermediate dialdehydes.A differentiation of the hydroxy groups is accomplished by lipase-mediated acetylation. For products (IV) and (IX) the enzymatic reaction proceeds with >99% regioselectivity. Surprisingly, the acylations proceed without any enantioselectivity. -(BECHEANU, A.; BARO, A.; LASCHAT*, S.; FREY, W.; Eur.