Intramolecular reductive cyclization of unsaturated keto- or aldo-esters by samarium(<scp>II</scp>) di-iodide: a ready synthesis of bicyclic γ-lactones
Treatment of unsaturatedketo- or aldo-esters with Sml2 in tetrahydrofuran (THF) or THF–hexamethylphosphoramide affords bicyclicγ-lactones in moderate to good yields.
By means of an intramolecular Baylis-Hillman reaction the cyclopentene derivative 1 has been formed from 2. Asymmetric induction is low (entry 12, table 1). In the sixmembered ring example 9 --> 10 the yield is only 17% - 23% (entries 1 and 2, table 2).
Organotin Hydride Catalyzed Carbon−Carbon Bond Formation: Radical-Mediated Reductive Cyclization of Enals and Enones
作者:David S. Hays、Gregory C. Fu
DOI:10.1021/jo951827s
日期:1996.1.1
Studies in the regioselectivity of the vinylogous Reformatsky reaction with ambident electrophiles: reversibility, mechanism, and synthetic utility
作者:Tomas Hudlicky、Michael G. Natchus、Larry D. Kwart、Barry L. Colwell