Carbonylation of Alkynyl Epoxides: Synthesis of 5-Hydroxy-2,3-dienoate Esters and 2,3-Dihydrofuran-3-ol Derivatives
摘要:
The carbonylation of alkynyl oxiranes catalyzed by (MePh2)(4)Pd in the presence of 20 atm of carbon monoxide in methanol gives methyl 5-hydroxy-2,3-pentadienoates in good yields. When the reaction is performed on alkynyl oxiranemethanol derivatives, 4,5-dihydrofuran-3-ol derivatives are obtained stereoselectively. These products arise from the spontaneous cyclization of a dihydroxyallenyl ester intermediate.
Highly efficient dynamic kinetic resolution of secondary aromatic alcohols at low temperature using a low-cost sulfonated sepiolite as racemization catalyst
作者:Jian-Ping Wu、Xiao Meng、Liang Wang、Gang Xu、Li-Rong Yang
DOI:10.1016/j.tetlet.2014.07.102
日期:2014.9
A highly efficient dynamic kineticresolution system for secondary aromatic alcohol using low-cost sulfonated sepiolite as a racemization catalyst has been developed. The system operates at 25 °C, achieves good eep (>99%) and substrate conversion ratio (>99%), is applicable to a variety of substrates and can be reused more than 10 times.