The present disclosure provides, inter alia, methods for preparing formaldehyde from carbon dioxide using bis(silyl)acetals, methods for incorporating carbon derived from carbon dioxide into a complex organic molecule derived from formaldehyde using bis(silyl)acetals, and methods for generating an isotopologue of a complex organic molecule derived from formaldehyde using bis(silyl)acetals.

The object of the present invention is to provide a process for preparing a 5-alken-1-yne compound efficiently at low costs and a process for preparing (2E,6Z)-2,6-nonadienal by making use of the aforesaid process for preparing the 5-alken-1-yne compound. There is provided a process for preparing a 5-alken-1-yne compound of the following formula (4): YZCR.sup.1CR.sup.2(CH.sub.2).sub.2CCH (4) in which Y in formula (4) represents a hydrogen atom or a hydroxyl group, the process comprising at least steps of: subjecting (i) an alkenylmagnesium halide compound prepared from a haloalkene compound of the following formula (1): YZCR.sup.1CR.sup.2(CH.sub.2).sub.2X.sup.1 (1) and (ii) an alkyne compound of the following formula (2): X.sup.2CCSi(R.sup.3)(R.sup.4)(R.sup.5) (2) to a coupling reaction to form a silane compound of the following formula (3): YZCR.sup.1CR.sup.2(CH.sub.2).sub.2CCSi(R.sup.3)(R.sup.4)(R.sup.5) (3); and subjecting the silane compound (3) to a desilylation reaction to form the 5-alken-1-yne compound (4).

The object of the present invention is to provide a process for preparing a 5-alken-1-yne compound efficiently at low costs and a process for preparing (2E,6Z)-2,6-nonadienal by making use of the aforesaid process for preparing the 5-alken-1-yne compound. There is provided a process for preparing a 5-alken-1-yne compound of the following formula (4): YZCR.sup.1CR.sup.2(CH.sub.2).sub.2CCH (4) in which Y in formula (4) represents a hydrogen atom or a hydroxyl group, the process comprising at least steps of: subjecting (i) an alkenylmagnesium halide compound prepared from a haloalkene compound of the following formula (1): YZCR.sup.1CR.sup.2(CH.sub.2).sub.2X.sup.1 (1) and (ii) an alkyne compound of the following formula (2): X.sup.2CCSi(R.sup.3)(R.sup.4)(R.sup.5) (2) to a coupling reaction to form a silane compound of the following formula (3): YZCR.sup.1CR.sup.2(CH.sub.2).sub.2CCSi(R.sup.3)(R.sup.4)(R.sup.5) (3); and subjecting the silane compound (3) to a desilylation reaction to form the 5-alken-1-yne compound (4).

Disclosed herein are synthesis methods for coelenterazine. Also disclosed are articles including the coelenterazine and coelenterazine derivatives. Representative absorbent articles include disposable diapers and adult incontinence products.

Disclosed herein are synthesis methods for coelenterazine. Also disclosed are articles including the coelenterazine and coelenterazine derivatives. Representative absorbent articles include disposable diapers and adult incontinence products.

There are provided methods of efficiently producing compounds that are, for example, sex pheromones of San Jose Scale. For example, there is provided a method for producing a 7-methyl-3-methylene-7-octenyl carboxylate compound (4), the method including the steps of: hydrolyzing a 7-methyl-3-methylene-7-octenal acetal compound (1) to obtain 7-methyl-3-methylene-7-octenal (2); reducing the 7-methyl-3-methylene-7-octenal (2) to obtain 7-methyl-3-methylene-7-octenol (3); and esterifying the 7-methyl-3-methylene-7-octenol (3) to obtain a 7-methyl-3-methylene-7-octenyl carboxylate compound (4).

##STR00001##

There are provided methods of efficiently producing compounds that are, for example, sex pheromones of San Jose Scale. For example, there is provided a method for producing a 7-methyl-3-methylene-7-octenyl carboxylate compound (4), the method including the steps of: hydrolyzing a 7-methyl-3-methylene-7-octenal acetal compound (1) to obtain 7-methyl-3-methylene-7-octenal (2); reducing the 7-methyl-3-methylene-7-octenal (2) to obtain 7-methyl-3-methylene-7-octenol (3); and esterifying the 7-methyl-3-methylene-7-octenol (3) to obtain a 7-methyl-3-methylene-7-octenyl carboxylate compound (4).

##STR00001##

Provided herein are convenient and efficient processes for preparing (2E,6Z)-2,6-nonadienal and (2E)-6,7-epoxy-2-nonenal with a reduced number of steps. For instance, provided herein is a process for preparing (2E,6Z)-2,6-nonadienal, including at least steps of subjecting a (6,6-dialkoxy-4-hexenylidene)triarylphosphorane compound of the general formula: Ar.sub.3PCH(CH.sub.2).sub.2CHCHCH(OR.sup.1)(OR.sup.2) to a Witting reaction with propanal to form a 1,1-dialkoxy-(6Z)-2,6-nonadiene compound of the general formula (6); and subjecting the 1,1-dialkoxy-(6Z)-2,6-nonadiene compound to hydrolysis to form (2E,6Z)-2,6-nonadienal. Also provided is a process for preparing (2E)-cis-6,7-epoxy-2-nonenal of the formula (8), comprising a step of subjecting (2E,6Z)-2,6-nonadienal thus obtained to epoxidation to form (2E)-cis-6,7-epoxy-2-nonenal. ##STR00001##

Provided herein are convenient and efficient processes for preparing (2E,6Z)-2,6-nonadienal and (2E)-6,7-epoxy-2-nonenal with a reduced number of steps. For instance, provided herein is a process for preparing (2E,6Z)-2,6-nonadienal, including at least steps of subjecting a (6,6-dialkoxy-4-hexenylidene)triarylphosphorane compound of the general formula: Ar.sub.3PCH(CH.sub.2).sub.2CHCHCH(OR.sup.1)(OR.sup.2) to a Witting reaction with propanal to form a 1,1-dialkoxy-(6Z)-2,6-nonadiene compound of the general formula (6); and subjecting the 1,1-dialkoxy-(6Z)-2,6-nonadiene compound to hydrolysis to form (2E,6Z)-2,6-nonadienal. Also provided is a process for preparing (2E)-cis-6,7-epoxy-2-nonenal of the formula (8), comprising a step of subjecting (2E,6Z)-2,6-nonadienal thus obtained to epoxidation to form (2E)-cis-6,7-epoxy-2-nonenal. ##STR00001##

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.