Stereoselective reduction of β hydroxyketones to 1,3-diols highly selective 1,3-asymmetric induction via boron chelates
作者:Koichi Narasaka、Fong-Chang Pai
DOI:10.1016/0040-4020(84)80006-x
日期:1984.1
Highly selective asymmetric induction can be achieved in the reduction of acyclic β-hydroxyketones via boron chelates. Treatment of β-hydroxyketones (1) with tributyl or tri-isobutylborane and successively with sodium borohydride afforded syn-1,3-diols (3) in highly stereo-selective manner, Syn -α-substituted-β -hydroxyketones (8) were also reduced to give syn, syn-1,3-diols (9) exclusively. The reaction
catalytic asymmetric aldolreaction of pyruvic aldehyde dimethyl acetal and 2-acetylthiazole with sugar aldehydes is demonstrated to be the key step in the synthesis of 3-deoxy-2-ulosonic acids. Efficient and stereoselective pyruvate aldolreactions are catalyzed by metal-based chiral Trost and Shibasaki catalysts. The presented synthetic methodology mimics aldolase-catalyzed reactions by direct activation