Synthesis 2010(20): 3509-3519  
DOI: 10.1055/s-0030-1258206
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Copper(I)-Catalyzed Intramolecular Caryl-O Bond-Forming Cyclization for the Synthesis of 1,4-Benzodioxines and Its Application in the Total Synthesis of Sweetening Isovanillins

Ajay B. Naidu, D. Ganapathy, Govindasamy Sekar*
Department of Chemistry, Indian Institute of Technology Madras, Chennai, Tamil Nadu-600 036, India
Fax: +91(44)22574202; e-Mail: gsekar@iitm.ac.in;
Further Information

Publication History

Received 15 June 2010
Publication Date:
13 August 2010 (online)

Abstract

Various substituted 1,4-benzodioxines were synthesized through an Ullmann-type intramolecular Caryl-O coupling cyclization reaction using a catalytic amount of BINOL-CuI complex. This methodology was successfully utilized as the key step in the total synthesis of isovanillyl sweetening agents 5-(2,3-dihydro-1,4-benzodioxin-2-yl)-2-methoxyphenol and 5-(2,3-dihydro-1,4-benz­oxathiin-2-yl)-2-methoxyphenol in 15.8% and 14.85% overall yields in five steps from isovanillin.