Shown and described are improved processes for the preparation of dapagliflozin of Formula I, ##STR00001##
or its solvates or co-crystals thereof and intermediates and their use in the preparation of dapagliflozin of Formula I or its solvates or co-crystals thereof.

Shown and described are improved processes for the preparation of dapagliflozin of Formula I, ##STR00001##
or its solvates or co-crystals thereof and intermediates and their use in the preparation of dapagliflozin of Formula I or its solvates or co-crystals thereof.

A production method of α,α-difluoroacetaldehyde according to the present invention includes reaction of an α,α-difluoroacetic acid ester with hydrogen gas (H.sub.2) in the presence of a ruthenium catalyst. It is possible to selectively obtain α,α-difluoroacetaldehyde as a partially reduced product of the hydrogenation reaction by the adoption of specific reaction conditions (in particular, reaction solvent and reaction temperature). This hydrogenation process can be alternative to the industrially unpractical hydride reduction process.

A production method of α,α-difluoroacetaldehyde according to the present invention includes reaction of an α,α-difluoroacetic acid ester with hydrogen gas (H.sub.2) in the presence of a ruthenium catalyst. It is possible to selectively obtain α,α-difluoroacetaldehyde as a partially reduced product of the hydrogenation reaction by the adoption of specific reaction conditions (in particular, reaction solvent and reaction temperature). This hydrogenation process can be alternative to the industrially unpractical hydride reduction process.

A production method of α,α-difluoroacetaldehyde according to the present invention includes reaction of an α,α-difluoroacetic acid ester with hydrogen gas (H.sub.2) in the presence of a ruthenium catalyst. It is possible to selectively obtain α,α-difluoroacetaldehyde as a partially reduced product of the hydrogenation reaction by the adoption of specific reaction conditions (in particular, reaction solvent and reaction temperature). This hydrogenation process can be alternative to the industrially unpractical hydride reduction process.

Production apparatus of triptane includes: carbon dioxide recovery unit configured to recover carbon dioxide from air; hydrogen generation unit configured to electrolyze water by renewable electricity to generate hydrogen; carbon monoxide generation unit configured to generate carbon monoxide from recovered carbon dioxide and hydrogen generated; methanol generation unit configured to generate methanol from carbon monoxide generated and hydrogen generated; acetic acid generation unit configured to generate acetic acid by reacting methanol generated with recovered carbon dioxide or with carbon monoxide generated; acetone generation unit configured to generate acetone and carbon dioxide from acetic acid generated; pinacolone generation unit configured to generate pinacolone from acetone generated; Grignard reagent generation unit configured to generate Grignard reagent from methanol generated; trimethyl butanol generation unit configured to generate 2,3,3-trimethyl-2-butanol by reacting pinacolone generated with Grignard reagent generated; and triptane generation unit configured to generate 2,2,3-trimethylbutane from 2,3,3-trimethyl-2-butanol generated.

Production apparatus of triptane includes: carbon dioxide recovery unit configured to recover carbon dioxide from air; hydrogen generation unit configured to electrolyze water by renewable electricity to generate hydrogen; carbon monoxide generation unit configured to generate carbon monoxide from recovered carbon dioxide and hydrogen generated; methanol generation unit configured to generate methanol from carbon monoxide generated and hydrogen generated; acetic acid generation unit configured to generate acetic acid by reacting methanol generated with recovered carbon dioxide or with carbon monoxide generated; acetone generation unit configured to generate acetone and carbon dioxide from acetic acid generated; pinacolone generation unit configured to generate pinacolone from acetone generated; Grignard reagent generation unit configured to generate Grignard reagent from methanol generated; trimethyl butanol generation unit configured to generate 2,3,3-trimethyl-2-butanol by reacting pinacolone generated with Grignard reagent generated; and triptane generation unit configured to generate 2,2,3-trimethylbutane from 2,3,3-trimethyl-2-butanol generated.

The present invention relates to a process for preparing a 3-isopropenyl-6-heptenal compound of the following formula (2): wherein R.sup.1 represents a hydrogen atom or a methyl group, the process comprising: subjecting a 3-isopropenyl-6-heptenoate ester compound of the following formula (1): wherein R.sup.1 is as defined above, and R.sup.2 represents a monovalent hydrocarbon group having 1 to 10 carbon atoms, to a reduction reaction with a reducing agent to form the 3-isopropenyl-6-heptenal compound (2).

##STR00001##

The present invention relates to a process for preparing a 3-isopropenyl-6-heptenal compound of the following formula (2): wherein R.sup.1 represents a hydrogen atom or a methyl group, the process comprising: subjecting a 3-isopropenyl-6-heptenoate ester compound of the following formula (1): wherein R.sup.1 is as defined above, and R.sup.2 represents a monovalent hydrocarbon group having 1 to 10 carbon atoms, to a reduction reaction with a reducing agent to form the 3-isopropenyl-6-heptenal compound (2).

##STR00001##

The present invention relates to a process for preparing a 3-isopropenyl-6-heptenal compound of the following formula (2): wherein R.sup.1 represents a hydrogen atom or a methyl group, the process comprising: subjecting a 3-isopropenyl-6-heptenoate ester compound of the following formula (1): wherein R.sup.1 is as defined above, and R.sup.2 represents a monovalent hydrocarbon group having 1 to 10 carbon atoms, to a reduction reaction with a reducing agent to form the 3-isopropenyl-6-heptenal compound (2).

##STR00001##