Synthesis and Lewis acid catalyzed Claisen rearrangement of 2-(1,3-oxazolin-2-yl)-substituted allyl vinyl ethers

Allyl vinyl ethers containing an acceptor function in the 2-position are useful substrates for the Lewis acid-catalyzed Claisen rearrangement. The first synthesis of acyclic 2-(1,3-oxazolin-2-yl)-substituted allyl vinyl ethers is reported. The Lewis acid catalyzed Claisen rearrangement of these allyl vinyl ethers afforded the rearrangement products with low to moderate diastereo- and enantioselectivity. The catalyzed rearrangement of chiral allyl vinyl ethers was investigated. The combination of substrate- and catalyst-induced diastereoselectivity led to unexpected and unprecedented results. (C) 2003 Elsevier Science Ltd. All rights reserved.