Recent update on synthesis of spiro-heterocycles in alcohol using malononitrile as a building block

Abstract

Spiro-heterocycles represent an important class of heterocyclic compounds with diverse area of application. These types of heterocycles are found in nature and also available synthetically. Especially, pyran based spiro heterocycles are one such important class of heterocycles among others. Here, in our review we have tried to focus on the recent developments in the synthesis of spiro-heterocycles using malononitrile as a simple and effective building block. We have also focused on alcohol mediated reactions as in most of the cases, the organic compounds are soluble in alcohol. Most of the alcohols are cost effective, easily available and easy to handle.