Transannular Diels-Alder model studies on the total synthesis of chatancin. The furanophane approach. Part 1: Assembly of the acyclic substrates

Synthesis of three generations of model substrates with advancing similarit y to chatancin are presented. In the first two generations, an Ireland-Clai sen based six-step sequence supplied the trans-dienophile to be connected b y dithiane chemistry to furfurals. In the third generation, a homogeraniol based dienophile aldehyde was coupled with a dilithiated 3-furoic acid. Sub sequently, all three generations were concluded with similar functional gro up modifications as a preparation for a malonate-furyl chloride based macro cyclization. (C) 1999 Elsevier Science Ltd. All rights reserved.