Zincate-mediated rearrangement reaction of 2-(1-hydroxyalkyl)-1-alkylcyclopropanol
作者:Kenichi Nomura、Seijiro Matsubara
DOI:10.1039/b901043b
日期:——
A rearrangement of lithium alkoxide of 2-(1-hydroxyalkyl)-1-alkylcyclopropanol into lithium alkoxide of vic-diol was mediated with an organozincate complex.
Enantioselective Synthesis of 2-Methyl-1,2-<i>syn</i>- and 2-Methyl-1,2-<i>anti</i>-3-butenediols via Allene Hydroboration−Aldehyde Allylboration Reaction Sequences
作者:Ming Chen、Masaki Handa、William R. Roush
DOI:10.1021/ja904599h
日期:2009.10.21
The hydroboration of allene 7 with ((d)lpc)(z)BH at 0 degrees C provides the kinetic allylborane 12Z with >20:1 selectivity. However, when the hydroboration is performed at 85 degrees C, the kinetically formed allylborane isomerizes to give the thermodynamic allylborane 12E with >= 12:1 selectivity. Subsequent treatment of 12Z or 12E with aldehydes at -78 degrees C, followed by oxidative workup, provides the 2-methyl-1,2-diols 8 and 9 in good yield and with 80-92% e.e.
Zn/InCl<sub>3</sub>-Mediated Pinacol Cross-Coupling Reactions of Aldehydes with α,β-Unsaturated Ketones in Aqueous Media
作者:Yong-Sheng Yang、Zhi-Liang Shen、Teck-Peng Loh
DOI:10.1021/ol900619d
日期:2009.5.21
A zinc/indium chloride-mediated pinacol cross-coupling reaction between aldehyde and alpha,beta-unsaturated ketone in aqueous media was developed. The 1,2-diols were obtained in moderate to good yields with up to 93:7 diastereoselectivity.