The present invention relates to a method for producing a 3-methylcycloalkenone compound and a method for producing muscone. In the presence of a zirconium oxide catalyst, a diketone represented by the following general formula (1): ##STR00001##
wherein in formula (1), n represents 8, 9, 10, 11 or 12,
is subjected to a vapor-phase intramolecular condensation reaction, whereby a 3-methylcycloalkenone compound can be produced with high reaction efficiency. When a 3-methylcyclopentadecenone compound produced by this method is hydrogenated in a known manner, muscone can be produced efficiently.

The present invention relates to a method for producing a 3-methylcycloalkenone compound and a method for producing muscone. In the presence of a zirconium oxide catalyst, a diketone represented by the following general formula (1): ##STR00001##
wherein in formula (1), n represents 8, 9, 10, 11 or 12,
is subjected to a vapor-phase intramolecular condensation reaction, whereby a 3-methylcycloalkenone compound can be produced with high reaction efficiency. When a 3-methylcyclopentadecenone compound produced by this method is hydrogenated in a known manner, muscone can be produced efficiently.

Provided herein is a method for producing methyl pentenone (MPO) in high yield in a continuous mode in a fixed bed reactor having a plurality of sidewall injecting ports by reacting excess methyl ethyl ketone (MEK) with acetaldehyde in presence of a cation exchange resin catalyst, wherein the acetaldehyde is injected from the plurality of sidewall injecting ports of the reactor. The method is also effective in reducing the complete consumption of the catalyst during the course of the reaction.

Provided herein is a method for producing methyl pentenone (MPO) in high yield in a continuous mode in a fixed bed reactor having a plurality of sidewall injecting ports by reacting excess methyl ethyl ketone (MEK) with acetaldehyde in presence of a cation exchange resin catalyst, wherein the acetaldehyde is injected from the plurality of sidewall injecting ports of the reactor. The method is also effective in reducing the complete consumption of the catalyst during the course of the reaction.

Disclosed is a stabilized acyclic saccharide composite, which includes a LDH-based (layered double hydroxide-based) material and acyclic saccharides intercalated in interlayer regions of the LDH-based material. The acyclic saccharides stabilized and trapped in the LDH-based material give an opportunity for direct functionalization to other valuable molecules in the pharmaceutical, chemical or carbohydrate industries. Further, a novel pathway for saccharide transformation and aldol condensation without the drawbacks associated with enzymatic catalysts is achieved through the acyclic saccharides trapped by the LDH-based material.

Disclosed is a stabilized acyclic saccharide composite, which includes a LDH-based (layered double hydroxide-based) material and acyclic saccharides intercalated in interlayer regions of the LDH-based material. The acyclic saccharides stabilized and trapped in the LDH-based material give an opportunity for direct functionalization to other valuable molecules in the pharmaceutical, chemical or carbohydrate industries. Further, a novel pathway for saccharide transformation and aldol condensation without the drawbacks associated with enzymatic catalysts is achieved through the acyclic saccharides trapped by the LDH-based material.

A (Z)-solanone has the steric formula of: ##STR00001##
or ##STR00002##
with the name of (S,Z)-5-isopropyl-8-methyl-6,8-diene-2-one or (R,Z)-5-isopropyl-8-methyl-6,8-diene-2-one. A process for the preparation of the (Z)-type solanone and the use thereof in flavoring of cigarette shred are further disclosed. The process includes the following steps: (1) reacting isopentanal and methyl vinyl ketone, under the action of a catalyst and a co-catalyst, to give (S)-2-isopropyl-5-carbonylhexanal or (R)-2-isopropyl-5-carbonylhexanal; (2) reacting the (S)-2-isopropyl-5-carbonylhexanal or the (R)-2-isopropyl-5-carbonylhexanal obtained in step (1) with (iodomethyl)triphenylphosphonium iodide, to give (S,Z)-7-iodo-5-isopropyl-6-ene-2-one or (R,Z)-7-iodo-5-isopropyl-6-ene-2-one; and (3) reacting the (S,Z)-7-iodo-5-isopropyl-6-ene-2-one or the (R,Z)-7-iodo-5-isopropyl-6-ene-2-one obtained in step (2) with pinacol isopropenylborate in the presence of a catalyst to give the (Z)-solanone.

A (Z)-solanone has the steric formula of: ##STR00001##
or ##STR00002##
with the name of (S,Z)-5-isopropyl-8-methyl-6,8-diene-2-one or (R,Z)-5-isopropyl-8-methyl-6,8-diene-2-one. A process for the preparation of the (Z)-type solanone and the use thereof in flavoring of cigarette shred are further disclosed. The process includes the following steps: (1) reacting isopentanal and methyl vinyl ketone, under the action of a catalyst and a co-catalyst, to give (S)-2-isopropyl-5-carbonylhexanal or (R)-2-isopropyl-5-carbonylhexanal; (2) reacting the (S)-2-isopropyl-5-carbonylhexanal or the (R)-2-isopropyl-5-carbonylhexanal obtained in step (1) with (iodomethyl)triphenylphosphonium iodide, to give (S,Z)-7-iodo-5-isopropyl-6-ene-2-one or (R,Z)-7-iodo-5-isopropyl-6-ene-2-one; and (3) reacting the (S,Z)-7-iodo-5-isopropyl-6-ene-2-one or the (R,Z)-7-iodo-5-isopropyl-6-ene-2-one obtained in step (2) with pinacol isopropenylborate in the presence of a catalyst to give the (Z)-solanone.

The present invention is directed to inhibitors of tyrosinase, pharmaceutical compositions comprising such tyrosinase inhibitors, and methods of making and using the same. Specifically, included in the present invention are compositions of matter comprised of at least one 2,4-dihydroxybenzene analog, which inhibit the activity of tyrosinase and which inhibit the overproduction of melanin.

The present invention is directed to inhibitors of tyrosinase, pharmaceutical compositions comprising such tyrosinase inhibitors, and methods of making and using the same. Specifically, included in the present invention are compositions of matter comprised of at least one 2,4-dihydroxybenzene analog, which inhibit the activity of tyrosinase and which inhibit the overproduction of melanin.