One pot synthesis of pyran-based heterocycles from benzyl halides as key reagents

Abstract

Pyridine N-oxide and silver oxide have been demonstrated to be efficient and mild reagents for the one pot synthesis of pyran analogues from a variety of benzyl halides. Benzyl halides are oxidized in situ to aldehydes, which in turn undergo a three-component reaction with malanonitrile/ethylcyanoacetate and α-hydroxy C–H acids to yield pyran analogues. The attractive features of this process are mild reaction conditions, short reaction times, broad functional group tolerance, easy isolation of products and excellent yields. Thus, the current method utilizes benzyl halides as key reagents instead of benzaldehydes.