Synthesis 2007(23): 3692-3696  
DOI: 10.1055/s-2007-990881
PAPER
© Georg Thieme Verlag Stuttgart · New York

Chemistry of Acylals, Part IV: BF3-Catalyzed Formation of Substituted α,α′-Bis(arylmethylidene)cycloalkanones from Acylals and 1-Cycloalkenyl Trimethylsilyl Ethers

Leiv K. Sydnes*a, Gry S. Pedersena, Bjarte Holmelida, Marcel Sandberga,b
a Department of Chemistry, University of Bergen, Allégt. 41, 5007 Bergen, Norway
Fax: +4755589490; e-Mail: leiv.sydnes@kj.uib.no;
b Synthetica AS, Forskningsparken, Gaustadalléen 21, 0349 Oslo, Norway
Further Information

Publication History

Received 22 May 2007
Publication Date:
13 November 2007 (online)

Abstract

When mixtures of an aromatic aldehyde acylal and a 1-cycloalkenyl trimethylsilyl ether in dichloromethane were treated with boron trifluoride at room temperature, the corresponding α,α′-bis(arylmethylidene)cycloalkanones were formed. The yield was sensitive to both the acetal/ether ratio and the structure of the acylal. The best results, up to 97% yield, were obtained when acylals containing a diacetoxy moiety were reacted with 1-cyclohexenyl tri­methylsilyl ether with an acetal-to-ether ratio of 2:1.