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
Hydroxyketones and diketones have been reduced with lithium indium hydride to give meso-diols selectively. α-Hydroxyketones and α-diketones are reduced to meso-1,2-diols with high diastereoselectivities, whereas the selectivities of β-hydroxyketones and β-diketones are less satisfactory.
The application of difunctional organosilicon compounds to organic synthesis; 1,3-asymmetric induction in the reduction of β-hydroxy-ketones
作者:Saeed Anwar、Anthony P. Davis
DOI:10.1039/c39860000831
日期:——
A number of β-hydroxy-ketones were reduced to anti-1,3-diols with diastereoisomeric excesses exceeding 95%, by a method involving presumed intramolecular transfer of hydrogen from a silicon atom to the carbonyl carbon.
The epoxide opening reactions of erythro and threo epoxy alcohols with a variety of nucleophiles, both in the presence and absence of Ti(OiPr)4, were examined. In general, opening of threo epoxy alcohols proceeded faster and with higher selectivity than the same reaction with the corresponding erythro isomers.
A Novel Method for the In situ Generation of Alkoxydialkylboranes and Their Use in the Selective Preparation of 1,3-<i>syn</i>Diols
作者:Kau-Ming Chen、Karl G. Gunderson、Goetz E. Hardtmann、Kapa Prasad、Oljan Repic、Michael J. Shapiro
DOI:10.1246/cl.1987.1923
日期:1987.10.5
An in situ method for generating Et2BOCH3 from triethylborane and methanol without using any other catalysts is described. Using the Et2BOCH3 thus generated as a chelating agent, syn 1,3-diols are prepared in ≥ 98% stereochemical purity by reducing β-hydroxyketones with sodium borohydride.