Synthesen ausgehend von 1-Methoxybuten( 1)-in(3)

Starting with 1-methoxy-butene(l)-in(3) there are two possibilities for the synthesis of longchained [alpha], [beta]-unsaturated aldehyd-acetales. Both ways are described. The first involves the formation of the C-C-linkage by application of the acetylene-Grignard-synthesis, followed by partial hydrogenation. The second begins with the hydrogenation to 1-methoxy-butadiene, followed by methoxy-bromination to [gamma]-bromo-crotonaldehyde-acetal and its condensation with alkali-metalorganic compounds as sodium malonicester or alkali cyanide.