Provided are a novel acyclic carbene ligand for ruthenium complex formation; a ruthenium complex catalyst using the ligand; a method of using the complex as a catalyst in an ethylene-metathesis ethenolysis reaction; a method of preparing the ruthenium complex catalyst; and a method of preparing a linear alpha-olefin, the method including the step of reacting a linear or cyclic alkene compound in the presence of the ruthenium complex catalyst. The acyclic carbene ligand of the present invention and the ruthenium complex catalyst using the same have high selectivity and turnover number for terminal olefin formation in an ethylene-metathesis ethenolysis reaction, and thus linear α-olefins may be prepared with a high yield.

The present invention provides a process for preparing a (1,2-dimethyl-3-methylenecyclopentyl)acetate compound of the following general formula (3), wherein R represents a linear or branched alkyl group having 1 to 4 carbon atoms, the process comprising subjecting a haloacetaldehyde alkyl 2,3-dimethyl-2-cyclopentenyl acetal compound of the following general formula (1), wherein R is as defined above, and Y represents a halogen atom, to a dehydrohalogenation reaction in the presence of a base, followed by a rearrangement reaction to obtain a (1,2-dimethyl-2-cyclopentenyl)acetate compound of the following general formula (2), wherein R is as defined above, and subjecting the (1,2-dimethyl-2-cyclopentenyl)acetate compound (2) to an epoxidation reaction, followed by an isomerization reaction and then a methylenation reaction to obtain the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound of the following general formula (3). The present invention also provides a process for preparing (1,2-dimethyl-3-methylenecyclopentyl)acetaldehyde of the following formula (4), the process comprising the aforesaid process for preparing the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound (3), and converting an alkoxycarbonylmethyl group (i.e., —CH.sub.2C(═O)OR) of the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound (3) to a formylmethyl group (i.e., —CH.sub.2CHO) to obtain (1,2-dimethyl-3-methylenecyclopentyl)acetaldehyde (4).

##STR00001##

The present invention provides a process for preparing a (1,2-dimethyl-3-methylenecyclopentyl)acetate compound of the following general formula (3), wherein R represents a linear or branched alkyl group having 1 to 4 carbon atoms, the process comprising subjecting a haloacetaldehyde alkyl 2,3-dimethyl-2-cyclopentenyl acetal compound of the following general formula (1), wherein R is as defined above, and Y represents a halogen atom, to a dehydrohalogenation reaction in the presence of a base, followed by a rearrangement reaction to obtain a (1,2-dimethyl-2-cyclopentenyl)acetate compound of the following general formula (2), wherein R is as defined above, and subjecting the (1,2-dimethyl-2-cyclopentenyl)acetate compound (2) to an epoxidation reaction, followed by an isomerization reaction and then a methylenation reaction to obtain the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound of the following general formula (3). The present invention also provides a process for preparing (1,2-dimethyl-3-methylenecyclopentyl)acetaldehyde of the following formula (4), the process comprising the aforesaid process for preparing the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound (3), and converting an alkoxycarbonylmethyl group (i.e., —CH.sub.2C(═O)OR) of the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound (3) to a formylmethyl group (i.e., —CH.sub.2CHO) to obtain (1,2-dimethyl-3-methylenecyclopentyl)acetaldehyde (4).

##STR00001##

The present disclosure provides a process for the preparation of compounds of formula (III),

##STR00001##

compounds of formula (V),

##STR00002##

and corresponding salts of formula (IV).

##STR00003##

The compounds made by the methods and processes of the invention are particularly useful for administration in humans and animals.

The present disclosure provides a process for the preparation of compounds of formula (III),

##STR00001##

compounds of formula (V),

##STR00002##

and corresponding salts of formula (IV).

##STR00003##

The compounds made by the methods and processes of the invention are particularly useful for administration in humans and animals.

The present disclosure provides a process for the preparation of compounds of formula (III),

##STR00001##

compounds of formula (V),

##STR00002##

and corresponding salts of formula (IV).

##STR00003##

The compounds made by the methods and processes of the invention are particularly useful for administration in humans and animals.

The present disclosure relates to a process for preparing an alpha-substituted acrylate, the process comprising: a) combining starting materials comprising an alpha-(halomethyl) acrylate and an organozinc compound, thereby forming a product comprising the alpha-substituted acrylate.

The present disclosure relates to a process for preparing an alpha-substituted acrylate, the process comprising: a) combining starting materials comprising an alpha-(halomethyl) acrylate and an organozinc compound, thereby forming a product comprising the alpha-substituted acrylate.

The present disclosure relates to a process for preparing an alpha-substituted acrylate, the process comprising: a) combining starting materials comprising an alpha-(halomethyl) acrylate and an organozinc compound, thereby forming a product comprising the alpha-substituted acrylate.

The present disclosure relates to a process for preparing an alpha-substituted acrylate, the process comprising: a) combining starting materials comprising an alpha-(halomethyl) acrylate and an organoaluminum compound, thereby forming a product comprising the alpha-substituted acrylate.