Co-catalyzed reductive cyclization of azido and cyano substituted α,β-unsaturated esters with NaBH4: enantioselective synthesis of (R)-baclofen and (R)-rolipram
作者:Abhimanyu S. Paraskar、Arumugam Sudalai
DOI:10.1016/j.tet.2006.03.017
日期:2006.5
Sodiumborohydride in combination with a catalytic amount of CoCl2 has been found to be an excellent catalytic system in reductive cyclizations of suitably substituted azido and cyano groups of α,β-unsaturated esters to afford γ and δ-lactams in high yields. The process has been demonstrated for the enantioselective synthesis of (R)-baclofen, (R)-rolipram, and (R)-4-fluorophenylpiperidinone, a key
HClO<sub>4</sub>·SiO<sub>2</sub>-mediated Improved Isomerization of Glycidic Esters to α-Hydroxy-β,γ-unsaturated Esters: Application in the Formal Synthesis of (<i>R</i>)-Baclofen and β-Phenyl GABA Analogues
作者:Ranjan Basak、Suresh Dharuman、Y. Suman Reddy、Venkata Ramana Doddi、Yashwant D. Vankar
DOI:10.1246/cl.2012.325
日期:2012.3.5
An efficient isomerization of glycidic esters to corresponding allylic alcohols, viz. α-hydroxy-β,γ-unsaturated esters has been brought about using HClO4·SiO2. Five of these allylic alcohols underw...