Stereoselective synthesis of (+)-nephrosteranic acid, (+)-trans-cognac lactone, and (+)-trans-whisky lactone using a chiral cyclohexadienyl Ti compound. 
We present the stereoselective transfer of cyclohexadienyl from 3-metalated 1,4-cyclohexadienes to various aldehydes.  Lewis-acid-mediated "allylation" of aldehydes by treatment with 3-silylated and 3-stannylated 1,4-cyclohexadienes could not be achieved with high diastereoselectivity.  In contrast, cyclohexadienyl titanium compounds reacted with both aliphatic and aromatic aldehydes with good-to-excellent diastereoselectivities.  Reaction of a chiral TADDOL-derived (TADDOL, 2,2-dimethyl-alpha,alpha,alpha',alpha'-tetraphenyl-1,3-dioxolandimethanol) cyclohexadienyl Ti derivative with various aldehydes led to the corresponding homoallylic alcohols with excellent diastereo- and enantioselectivities.  Lower selectivities were obtained with chiral B-cyclohexadienyldiisopinocampheylborane.  The 1,3-cyclohexadienes are very useful building blocks for the preparation of biologically important gamma-butyrolactones.  Short efficient syntheses of (+)-nephrosteranic acid, (+)-trans-whisky lactone, and (+)-trans-cognac lactone by desymmetrization of 1,4-cyclohexadiene are described.