Process for preparing a 5-alken-1-yne compound, (6z)-1,1-dialkoxy-6-nonen-2-yne compound, (2e,6z)-2,6-nonadienal and (2e)-cis-6,7-epoxy-2-nonenal, and 1,1-dialkoxy-6-nonen-2-yne compound

Abstract

The object of the present invention is to provide a process for preparing a 5-alken-1-yne compound efficiently at low costs and a process for preparing (2E,6Z)-2,6-nonadienal by making use of the aforesaid process for preparing the 5-alken-1-yne compound. There is provided a process for preparing a 5-alken-1-yne compound of the following formula (4): Y—Z—CR═CR—(CH)—C≡CH (4) in which Y in formula (4) represents a hydrogen atom or a hydroxyl group, the process comprising at least steps of: subjecting (i) an alkenylmagnesium halide compound prepared from a haloalkene compound of the following formula (1): Y—Z—CR═CR—(CH)—X(1) and (ii) an alkyne compound of the following formula (2): X—C≡C—Si(R)(R)(R) (2) to a coupling reaction to form a silane compound of the following formula (3): Y—Z—CR═CR—(CH)—C≡C—Si(R)(R)(R) (3); and subjecting the silane compound (3) to a desilylation reaction to form the 5-alken-1-yne compound (4).