This application is directed to use of transition metal-ligand complexes to hydrogenate fluorinated esters and carboxamides into fluorinated hemiacetals. Methods for synthesis of certain ligands are also provided.

This application is directed to use of transition metal-ligand complexes to hydrogenate fluorinated esters and carboxamides into fluorinated hemiacetals. Methods for synthesis of certain ligands are also provided.

Disclosed is a method for preparing a 2-fluoroacrylate, comprising the steps of: (1) mixing a vinyl ether having the structure of formula A with dichloromonofluoromethane to yield a substituted cyclopropane compound having the structure of formula B; (2) mixing the substituted cyclopropane compound having the structure of formula B with R.sup.2OH to yield an acetal product having the structure of formula C, followed by hydrolysis to yield 2-fluoroacrylaldehyde having the structure of formula D; or reacting the substituted cyclopropane compound having the structure of formula B with water to yield 2-fluoroacrylaldehyde having the structure of formula D via hydrolysis; (3) oxidizing 2-fluoroacrylaldehyde having the structure of formula D to yield 2-fluoroacrylic acid having the structure of formula E; and (4) mixing 2-fluoroacrylic acid having the structure of formula E with R.sup.3OH to yield a 2-fluoroacrylate having the structure of formula F.

Disclosed is a method for preparing a 2-fluoroacrylate, comprising the steps of: (1) mixing a vinyl ether having the structure of formula A with dichloromonofluoromethane to yield a substituted cyclopropane compound having the structure of formula B; (2) mixing the substituted cyclopropane compound having the structure of formula B with R.sup.2OH to yield an acetal product having the structure of formula C, followed by hydrolysis to yield 2-fluoroacrylaldehyde having the structure of formula D; or reacting the substituted cyclopropane compound having the structure of formula B with water to yield 2-fluoroacrylaldehyde having the structure of formula D via hydrolysis; (3) oxidizing 2-fluoroacrylaldehyde having the structure of formula D to yield 2-fluoroacrylic acid having the structure of formula E; and (4) mixing 2-fluoroacrylic acid having the structure of formula E with R.sup.3OH to yield a 2-fluoroacrylate having the structure of formula F.

An efficient process for preparing (9E,11Z)-9,11-hexadecadienal of formula (4) ##STR00001##
is provided. The process includes at least steps of: conducting a nucleophilic substitution reaction between an (8E,10Z)-8,10-pentadecadienyl magnesium halide derived from an (8E,10Z)-1-halo-8,10-pentadecadiene of (1): ##STR00002##
and an orthoformate ester (2) ##STR00003##
to thereby prepare a (9E, 11Z)-1,1-dialkoxy-9, 11-hexadecadiene (3): ##STR00004##
and hydrolyzing the (9E, 11Z)-1,1-dialkoxy-9,11-hexadecadiene (3) to obtain (9E, 11Z)-9,11-hexadecadienal (4).

An efficient process for preparing (9E,11Z)-9,11-hexadecadienal of formula (4) ##STR00001##
is provided. The process includes at least steps of: conducting a nucleophilic substitution reaction between an (8E,10Z)-8,10-pentadecadienyl magnesium halide derived from an (8E,10Z)-1-halo-8,10-pentadecadiene of (1): ##STR00002##
and an orthoformate ester (2) ##STR00003##
to thereby prepare a (9E, 11Z)-1,1-dialkoxy-9, 11-hexadecadiene (3): ##STR00004##
and hydrolyzing the (9E, 11Z)-1,1-dialkoxy-9,11-hexadecadiene (3) to obtain (9E, 11Z)-9,11-hexadecadienal (4).

An efficient process for preparing (9E,11Z)-9,11-hexadecadienal of formula (4)

##STR00001##

is provided. The process includes at least steps of: conducting a nucleophilic substitution reaction between an (8E,10Z)-8,10-pentadecadienyl magnesium halide derived from an (8E,10Z)-1-halo-8,10-pentadecadiene of (1):

##STR00002##

and an orthoformate ester (2)

##STR00003##

to thereby prepare a (9E, 11Z)-1,1-dialkoxy-9, 11-hexadecadiene (3):

##STR00004##

and hydrolyzing the (9E, 11Z)-1,1-dialkoxy-9,11-hexadecadiene (3) to obtain (9E, 11Z)-9,11-hexadecadienal (4).

An efficient process for preparing (9E,11Z)-9,11-hexadecadienal of formula (4)

##STR00001##

is provided. The process includes at least steps of: conducting a nucleophilic substitution reaction between an (8E,10Z)-8,10-pentadecadienyl magnesium halide derived from an (8E,10Z)-1-halo-8,10-pentadecadiene of (1):

##STR00002##

and an orthoformate ester (2)

##STR00003##

to thereby prepare a (9E, 11Z)-1,1-dialkoxy-9, 11-hexadecadiene (3):

##STR00004##

and hydrolyzing the (9E, 11Z)-1,1-dialkoxy-9,11-hexadecadiene (3) to obtain (9E, 11Z)-9,11-hexadecadienal (4).

Disclosed is an industrial method for efficient production of an ,-difluoroaldehyde compound, which includes reaction of an ,-difluoroacetate with hydrogen gas (H.sub.2) in the presence of a ruthenium catalyst and a base. By the adoption of specific reaction conditions (catalyst, base, pressure etc.), it is possible to produce the target ,-difluoroaldehyde compound with a high conversion rate and high selectivity.

Disclosed is an industrial method for efficient production of an ,-difluoroaldehyde compound, which includes reaction of an ,-difluoroacetate with hydrogen gas (H.sub.2) in the presence of a ruthenium catalyst and a base. By the adoption of specific reaction conditions (catalyst, base, pressure etc.), it is possible to produce the target ,-difluoroaldehyde compound with a high conversion rate and high selectivity.