Stereodirected Reactions of Salicilaldehyde Derivatives with tert-Butyl 3(4)-Hydroxy-2(3)-(3-methylbut-2-enyl)-piperidine-1-carboxylates as an Efficient Preparation Procedure of Tetrahydropyran Derivatives Fused with a Piperidine Ring

摘要

Reaction of salicilaldehyde and its derivatives with unsaturated cis-, trans-alcohols of the piperidine series in the presence of methyl orthoformate and p-toluenesulfonic acid led to the formation of a new heterocyclic system connecting four fuzed rings (two tetrahydropyrans, a piperidine, and an aromatic ring), 6,6-dimethyl-6a, 7,7a, 8(9), 10,11,11a, 12a-octahydrochromeno[3',4':5,6] pyran.[3,2-c(b)] pyridine.