PAPER	Synthesis 2004: 2711-2715   DOI: 10.1055/s-2004-831220
© Georg Thieme Verlag Stuttgart · New York
Rapid and Efficient Protocol for the Synthesis of 4-Chlorotetrahydropyrans Using Niobium(V) Chloride
J. S. Yadav*, B. V. Subba Reddy, Manoj Kumar Gupta, Swapan Kumar Biswas
Division of Organic Chemistry, Indian Institute of Chemical Technology, Hyderabad-500007, India Fax: +91(40)27160512; e-Mail: yadavpub@iict.res.in;
Received 28 May 2004

Abstract

Aldehydes undergo a rapid coupling with 3-buten-1-ol utilizing 20 mol% of niobium(V) chloride to afford 4-chlorotetrahydropyran derivatives under extremely mild conditions within short reaction times in excellent yields with high selectivity. The similar halogenated tetrahydropyrans are also obtained using gallium(III) halides.

Keywords

Prins-cyclization - niobium(V) chloride - gallium(III) halides - halogenated tetrahydropyrans