2008 Oxazole derivatives R 0220 Intramolecular Conjugate Addition of γ- and δ-Trichloroacetimidoyloxy-α,β-UnEsters in an Acyclic System. — A new method for the introduction of a 41- 128 saturated nitrogen functionality on the β-carbon of γ- and δ-hydroxy-α,β-unsaturated esters is presented as a novel way to construct 1,2-amino or 1,3-amino alcohol moieties in an acyclic system. Intramolecular conjugate addition of γ- and δ-trichloroacetimidoyloxy-α,ß-unsaturated esters is achieved using different bases. In the presence of DBU, oxazolines with cis-stereoselectivity are formed predominantly. Using tBuOK as a base, stereoselectivity is degraded up to reversed. The present new method is the key step in the synthesis of D-vancosamine (XVII) and its 3-epimer. — (MATSUSHIMA*, Y.; KINO, J.; Tetrahedron 64 (2008) 18, 3943-3952; Dep. Chem., Hamamatsu Univ. Sch. Med., Hamamatsu 431, Japan; Eng.) — S. Adam 2008