PAPER	Synthesis 2006: 2497-2502   DOI: 10.1055/s-2006-942465
© Georg Thieme Verlag Stuttgart · New York
Silica-Supported Perchloric Acid (HClO4-SiO2): A Versatile Catalyst for Tetrahydropyranylation, Oxathioacetalization and Thioacetalization
Abu T. Khan*, Tasneem Parvin, Lokman H. Choudhury
Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781 039, India Fax: +91(361)2690762; e-Mail: atk@iitg.ernet.in;
Received 10 February 2006

Abstract

A simple and convenient synthetic protocol for the protection of hydroxyl group as tetrahydropyranyl ether as well as carbonyl functionality as oxathioacetal and thioacetal has been achieved using a catalytic amount of silica-supported perchloric acid under solvent-free conditions. This protocol has many advantages compared to currently available methodologies in terms of simplicity, yield, reaction time, reusability of the catalyst and economic viability.

Key words

alcohols - phenols - THP ethers - carbonyl compounds - oxathioacetals - thioacetals