A highly diastereoselective Tandem radical reaction. Facile three-component routes to protected (E)-polysubstituted homoallylic alcohols

A facile synthesis of geometrically pure (E)-1,2,4-trisubstituted and (E)-1,2,4-tetrasubstituted homoallylic benzoates was developed. Various Lewis acids were subsequently evaluated in the diastereoselective radical substitution of (E)-β-nitrostyrene, and Titanium (IV) 2-ethylhexoxide emerged as the best Lewis acid in terms of yield and diastereoselectivity (up to 98% de). These reactions occurred with high regio-, diastereo- and stereoselectivity, and a possible mechanism to explain this transformation was proposed.