Disclosed is a cyclopropanation process comprising the step of reacting an alkene compound having at least one carbon-carbon double bond with at least one dihaloalkane. The reaction is carried out in the presence of (i) particulate metal Zn, (ii) catalytically effective amount of particulate metal Cu or a salt thereof, (iii) at least one haloalkylsilane, and (iv) at least one solvent.

Disclosed is a cyclopropanation process comprising the step of reacting an alkene compound having at least one carbon-carbon double bond with at least one dihaloalkane. The reaction is carried out in the presence of (i) particulate metal Zn, (ii) catalytically effective amount of particulate metal Cu or a salt thereof, (iii) at least one haloalkylsilane, and (iv) at least one solvent.

The present invention discloses a method for preparing optically active carbonyl compound, comprising the following steps: under the catalysis of chiral amine salt and transition metal catalysts, with hydrogen and catalytic amount of dihydropyridine compound as hydrogen source, use , -unsaturated aldehydes or , -unsaturated troponoid compounds to conduct asymmetric catalytic reaction to obtain the optically active carbonyl compound. This method comes in moderate reaction condition, simple operation, and catalytic amount of dihydropyridine compounds usage, the target product is easy to be separated and purified from the reaction system, and the metal catalyst can be recycled, it is economical.

The present invention discloses a method for preparing optically active carbonyl compound, comprising the following steps: under the catalysis of chiral amine salt and transition metal catalysts, with hydrogen and catalytic amount of dihydropyridine compound as hydrogen source, use , -unsaturated aldehydes or , -unsaturated troponoid compounds to conduct asymmetric catalytic reaction to obtain the optically active carbonyl compound. This method comes in moderate reaction condition, simple operation, and catalytic amount of dihydropyridine compounds usage, the target product is easy to be separated and purified from the reaction system, and the metal catalyst can be recycled, it is economical.

The present disclosure relates to methods and intermediates useful for preparing a compound of formula I:

##STR00001##

or a co-crystal, solvate, salt or combination thereof.

The present disclosure relates to methods and intermediates useful for preparing a compound of formula I:

##STR00001##

or a co-crystal, solvate, salt or combination thereof.