11-halo-3-undecene compound and a process for preparing the same and a process for preparing 9-dodecenal compound

A process for preparing a (9Z)- or (9E)-9-dodecenal compound of the following formula (4):

• CH3CH2CH═CH(CH2)7CHO (4)
• the process comprising steps of
• subjecting a nucleophilic reagent, a (3Z)- or (3E)-3-hexenyl compound, of the following general formula (5):
• CH3CH2CH═CH(CH2)2M2 (5)
• in which M2 represents Li or MgZ2, wherein Z2 represents a halogen atom or a 3-hexenyl group, to a coupling reaction with a 1-halo-5-halopentane compound of the general formula (6):
• X3(CH2)5X4 (6)
• in which X3 represents a chlorine atom and X4 represents a bromine atom,
• in the presence of a cuprous halide and a trialkyl phosphite compound having 3 to 9 carbon atoms to produce a (3Z)- or (3E)-11-halo-3-undecene compound of the following general formula (7):
• CH3CH2CH═CH(CH2)7X1 (7)
• in which X1 represents a chlorine atom;
• and
• preparing the nucleophilic reagent, (8Z)- or (8E)-8-undecenyl compound of the following general formula (1);
• CH3CH2CH═CH(CH2)7M1 (1)
• in which M1 represents Li or MgZ1, wherein Z1 represents a halogen atom or an 8-undecenyl group,
• from the (3Z)- or (3E)-11-chloro-3-undecene compound (7) thus obtained, respectively;
• subjecting the nucleophilic reagent, (8Z)- or (8E)-8-undecenyl compound (1) thus obtained to a nucleophilic substitution reaction with an orthoformic ester compound of the following general formula (2):
• in which R may be same with or different from each other and represents an alkyl group having 1 to 6 carbon atoms,
• to produce a (9Z)- or (9E)-1,1-dialkoxy-9-dodecene compound of the following general formula (3):
• CH3CH2CH═CH(CH2)7CH(OR)2 (3)
• in which R is as defined above, respectively;
• and
• hydrolyzing the (9Z)- or (9E)-1,1-dialkoxy-9-dodecene compound (3) thus obtained, in the presence of oxalic acid to produce the (9Z)- or (9E)-9-dodecenal compound (4), respectively.