A method for producing a bifunctional compound of formula (3) ##STR00001## wherein R.sub.2 represents H, CH.sub.3 or C.sub.2H.sub.5, the method comprising reducing a bifunctional compound of formula (1): ##STR00002## wherein R.sub.1 represents COOCH.sub.3, COOC.sub.2H.sub.5, COOC.sub.3H.sub.7, COOC.sub.4H.sub.9, or CHO; and R.sub.2 represents H, CH.sub.3 or C.sub.2H.sub.5, provided that when R.sub.1 represents CHO, R.sub.2 represents C.sub.2H.sub.5, in the presence of a catalyst having hydrogenation activity and hydrogen.

The present invention is able to provide a bifunctional compound represented by formula (I).

##STR00001## (In the formula, R.sub.1 represents COOCH.sub.3, COOC.sub.2H.sub.5, COOC.sub.3H.sub.7, COOC.sub.4H.sub.9 or CHO; and R.sub.2 represents H, CH.sub.3 or C.sub.2H.sub.5.)

The present invention is able to provide a bifunctional compound represented by formula (I).

##STR00001## (In the formula, R.sub.1 represents COOCH.sub.3, COOC.sub.2H.sub.5, COOC.sub.3H.sub.7, COOC.sub.4H.sub.9 or CHO; and R.sub.2 represents H, CH.sub.3 or C.sub.2H.sub.5.)

A production method for producing a target compound represented by the following formula (1), the production method including: a step (A) of subjecting a mixed liquid containing a starting compound represented by the following formula (2) and a solvent to a hydrogenation reduction in the presence of a catalyst having hydrogenation ability, wherein the solvent is a linear or branched secondary alcohol or tertiary alcohol:

##STR00001##

wherein R represents H, CH.sub.3, or C.sub.2H.sub.5,

##STR00002##

wherein R represents H, CH.sub.3, or C.sub.2H.sub.5, and R.sub.1 represents CH.sub.3, C.sub.2H.sub.5, C.sub.3H.sub.7, or C.sub.4H.sub.9.

A production method for producing a target compound represented by the following formula (1), the production method including: a step (A) of subjecting a mixed liquid containing a starting compound represented by the following formula (2) and a solvent to a hydrogenation reduction in the presence of a catalyst having hydrogenation ability, wherein the solvent is a linear or branched secondary alcohol or tertiary alcohol:

##STR00001##

wherein R represents H, CH.sub.3, or C.sub.2H.sub.5,

##STR00002##

wherein R represents H, CH.sub.3, or C.sub.2H.sub.5, and R.sub.1 represents CH.sub.3, C.sub.2H.sub.5, C.sub.3H.sub.7, or C.sub.4H.sub.9.

The present invention is able to provide a bifunctional compound represented by formula (1). ##STR00001##
(In the formula, R.sub.1 represents COOCH.sub.3, COOC.sub.2H.sub.5, COOC.sub.3H.sub.7, COOC.sub.4H.sub.9 or CHO; and R.sub.2 represents H, CH.sub.3 or C.sub.2H.sub.5.)

The present invention is able to provide a bifunctional compound represented by formula (1). ##STR00001##
(In the formula, R.sub.1 represents COOCH.sub.3, COOC.sub.2H.sub.5, COOC.sub.3H.sub.7, COOC.sub.4H.sub.9 or CHO; and R.sub.2 represents H, CH.sub.3 or C.sub.2H.sub.5.)

The present invention is able to provide a bifunctional compound represented by formula (1).

##STR00001##

(In the formula, R.sub.1 represents COOCH.sub.3, COOC.sub.2H.sub.5, COOC.sub.3H.sub.7, COOC.sub.4H.sub.9 or CHO; and R.sub.2 represents H, CH.sub.3 or C.sub.2H.sub.5.)

The present invention is able to provide a bifunctional compound represented by formula (1).

##STR00001##

(In the formula, R.sub.1 represents COOCH.sub.3, COOC.sub.2H.sub.5, COOC.sub.3H.sub.7, COOC.sub.4H.sub.9 or CHO; and R.sub.2 represents H, CH.sub.3 or C.sub.2H.sub.5.)

A method for producing a bifunctional compound of formula (1): ##STR00001##
where R.sub.1 represents COOCH.sub.3, COOC.sub.2H.sub.5, COOC.sub.3H.sub.7, COOC.sub.4H.sub.9 or CHO and R.sub.2 represents H, CH.sub.3 or C.sub.2H.sub.5, by subjecting a monoolefin of formula (2): ##STR00002##
where R.sub.1 represents COOCH.sub.3, COOC.sub.2H.sub.5, COOC.sub.3H.sub.7, COOC.sub.4H.sub.9 or CHO and R.sub.2 represents H, CH.sub.3 or C.sub.2H.sub.5, carbon monoxide and hydrogen gases to a hydroformylation reaction in the presence of a rhodium compound and an organic phosphorous compound. Compounds produced.