Asymmetric synthesis of a (2Z,7E)-cyclononadiene by an intramolecular cycloalkylation and insight to its conformational properties

[GRAPHICS] Here, we report a novel synthesis of a monosubstituted, enantio and diaster eomerically enriched transcyclononadienol. The reaction consists of an enan tioselective (-)-sparteine-mediated allylic lithiation of an achiral 7-chlo rononadienyl carbamate and a subsequent stereospecific intramolecular allyl lithium-allyl chloride coupling. The stereochemical course of the cyclizati on has been determined, and the high configurative stability of the chiral nine membered carbocycle has been investigated by kinetic measurements and rationalized by computational calculations.