A straightforward synthesis of (E)-δ-alkenyl-β,γ-unsaturated δ-lactones by a tandem ring-closing/cross-coupling metathesis process
摘要:
The access to (E)-delta-alkenyl-beta,gamma-unsaturated delta-lactones starting from 3-O-(1,4-pentadienyl) 3-butenoate has been investigated by using a tandem process including two different metathesis reactions. By this way, new structures, isomers of natural compounds like argentilactone, were isolated in good yields. Reconjugation of the internal C=C bond can be achieved under basic conditions to give alpha-pyrones. (C) 2003 Elsevier Ltd. All rights reserved.