Silicon-mediated highly efficient synthesis of 1,8-dioxo-octahydroxanthenes and their transformation to novel functionalized pyrano-tetrazolo1,5-aazepine derivatives

摘要

A facile and highly efficient protocol for the synthesis of 1,8-dioxo-octahydroxanthene derivatives was achieved through cascade Knoevenagel-Michael condensations and cyclo-dehydration reaction utilizing tetrachlorosilane(TCS) as catalyst under mild conditions.Reaction of the titled compounds with TCSNaN_3 to give novel functionalized pyrano[3,2-c]tetrazolo[1,5-a]azepine derivatives is also described.