956219-35-5Relevant academic research and scientific papers
Stereoselective synthesis of (+)-nephrosteranic acid, (+)-trans-cognac lactone, and (+)-trans-whisky lactone using a chiral cyclohexadienyl Ti compound
Schleth, Florian,Vogler, Thomas,Harms, Klaus,Studer, Armido
, p. 4171 - 4185 (2004)
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-α,α,α′,α′-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 β-cyclohexadienyldiisopinocampheylborane. The 1,3-cyclohexadienes are very useful building blocks for the preparation of biologically important γ-butyrolactones. Short efficient syntheses of (+)-nephrosteranic acid, (+)-trans-whisky lactone, and (+)-iram-cognac lactone by desymmetrization of 1,4-cyclohexadiene are described.
Desymmetrization of Metalated Cyclohexadienes and Application to the Synthesis of Nephrosteranic Acid
Schleth, Florian,Studer, Armido
, p. 313 - 315 (2007/10/03)
Chiral cyclohexadienyl Ti-TADDOLate reacts with aldehydes to provide the corresponding homoallyl alcohols in high yields with excellent diastereo- and high enantioselectivities (see scheme). The new method has been used as the key step in an efficient syn
