Abstract
1-Alkyl-2,3-dimethoxycarbonyl-1,3-butadienes 4 were synthesized via two different routes. In the first route, the Wittig-Horner reaction of the readily available phosphonate 2 with various aldehydes yielded the corresponding 1,3-dienes 4 with a good E stereoselectivity. The second route, using α-(bromomethyl) fumarate 1 under basic conditions, provides stereospecifically pure (E)-1,3-dienes 4.