AMPLIFICATION OF CHIRALITY BY TRANSITION-METAL COORDINATION - SYNTHESIS OF CHIRAL ALLENES AND ALLENE MANGANESE COMPLEXES OF HIGH ENANTIOMERIC PURITY - SYNTHESIS OF METHYL (R,E)-(-)-(2,4,5-TETRADECATRIENOATE (PHEROMONE OF ACANTHOSCELIDES-OBTECTUS (SAY))

The enhancement of the asymmetry of chiral allenes by coordination wit h a transition metal can be turned to account for (easy) resolution of the complexes and therefore the allenes themselves. This is illustrat ed here on allene aldehyde complexes of (eta-methylcyclopentadienyl) d icarbonylmanganese, possibly bearing a second electron withdrawing sub stituent, and by the synthesis of an optically active alkenylallenic i nsect pheromone of high enantiomeric purity. (C) 1998 Elsevier Science Ltd. All rights reserved.