Bromine-Induced Facile Synthesis of Butenolides and Spirobutenolides from Sterically Congested Tetrasubstituted Dialkyl Alkylidene Succinates
作者:Narshinha Argade、Ramesh Patel
DOI:10.1055/s-0029-1219233
日期:2010.4
Starting from sterically congested tetrasubstituted dialkyl alkylidene succinates, facile general approach to several dialkyl substituted butenolides and spirobutenolides with the generation of quaternary carbon center has been demonstrated via bromine-induced dealkylative regioselective intramolecular cyclization and dehydrobromination pathway. The mechanistic aspects involved in the formation of butenolides have been also described in brief.
Regio- and stereoselective selenium dioxide allylic oxidation of (E)-dialkyl alkylidenesuccinates to (Z)-allylic alcohols: Synthesis of natural and unnatural butenolides
作者:Ramesh M. Patel、Vedavati G. Puranik、Narshinha P. Argade
DOI:10.1039/c1ob05709j
日期:——
allylic alcohol formation of dialkyl alkylidenesuccinates has been demonstrated to accomplish one-stepsyntheses of several essential butenolides and fused butenolidesvia an unusual E- to Z- carbon–carbon double bond isomerisation followed by the lactonization pathway. The observed regio- and stereoselective SeO2 allylic oxidation protocol has also been extended to the diastereoselective total synthesis