Stereoselective preparation of 2-silylated 1,3-diols and the regioselectivity of their Peterson olefination

New Silicon Groups as Potential Chiral Auxiliaries. Synthesis and Highly Selective Chiral 1,6-Induction in 1,2-Additions to Acylsilanes

“…We have demonstrated previously, particularly with acylsilanes of type 1 (R reac = acyl), that silyl groups A (Figure ) with “silicon-centered” chirality and a silicon-bound alkoxymethyl substituent can act as powerful stereochemical directors in chelate-controlled diastereoselective transformations . A number of chiral carbon frameworks have been stereoselectively prepared with precursors possessing such groups, such as secondary alcohols, α,β-substituted δ-silylated γ,δ-unsaturated carboxylic acids, β,γ-substituted δ,ε-unsaturated acyl silanes, aldol type products and derivatives thereof, and β-chiral ketones . Of particular interest to us are chiral α-hydroxyallylsilanes of type 3 that are accessible in high enantiomeric purity by stereoselective addition of vinyl organometallic reagents to chiral acylsilanes of type 1 1 , combining the structural and chemical features of α-hydroxysilanes, allylsilanes, and allylic alcohols.…”

Reactions of Aldehydes and Ketones and Their Derivatives

“…(95)]. 223 Diols which are configured syn,anti [such as (95)] undergo highly regio-and stereo-selective Peterson olefination. The unexpected finding that reduction of cis-2,6-dimethylcyclohexanone with sodium borohydride in methanol gave predominantly the axial alcohol prompted a detailed investigation of the reaction.…”