Nazarov cyclisation of dienone-esters and tetrahydropyrones using trimethylsilyltriflate

Dienone- and tetrahydropyrone- esters undergo Nazarov-type cyclisation using trimethylsilyltriflate.

Cyclopentenone esters have been synthesized via a Nazarov cyclisation of the corresponding ,′-dienone esters or tetrahydro-γ-pyrone esters employing trimethylsilyltriflate at room temperature. The dienone esters were synthesised by a short two-step acylation-Knoevenagel sequence.