[3+3] Annulation of Diazoenals and α-Mercapto Ketones via Protic Sulfonium Ylides: Direct Synthesis of 2H-Thiopyrans, Innovative Progenitors for Unstudied 2H-Thiopyran-2-ones and 4H-Thiopyran-4-ones
Herein, we report a new Rh(II)/Sc(III)-catalyzed [3+3] annulation between diazoenals and α-mercapto ketones for the direct synthesis of 4-formyl-2H-thiopyrans. The reaction proceeds via protic sulfonium ylides derived from highly electrophilic Rh-enalcarbenoids, followed by regioselective intramolecular aldol condensation. Further studies revealed that 4-formyl-2H-thiopyrans are novel precursors for unstudied
作者:Yolante Z. Adamczewska、John M. Barker、Patrick R. Huddleston、Michael L. Wood
DOI:10.1080/00397919608003715
日期:1996.3
2-Acyl-3-hydroxythiophenes have been made by the reaction of the anion of a mercaptoketone with dimethyl acetylenedicarboxylate to give a hydroxythiophene ester which is then hydrolysed and decarboxylated.