Disclosed is a method of synthesizing a (1R,2R)-nitroalcohol compound of formula (I), as shown in the following reaction scheme, including: subjecting a compound of formula (II) and a compound of formula (III) to a condensation reaction in an organic solvent in the presence of a copper complex generated in situ from a chiral (1S,2R)-amino alcohol ligand and a cupric salt to produce the (1R,2R)-nitroalcohol compound of formula (I), where R.sup.1 and R.sup.2 are defined in the same manner as that in the specification. The method involves mild reaction conditions, excellent diastereoselectivity and high chemical yield, and thus it is suitable for industrial applications. ##STR00001##

Disclosed is a method for producing a trisulfide compound or a selenotrisulfide compound. This production method includes: a step for oxidizing a disulfide compound with an oxidizing agent to obtain a sulfoxide compound; and a step for reacting the sulfoxide compound that has been obtained with a source of sulfur or a source of selenium to obtain a trisulfide compound or a selenotrisulfide compound.

Disclosed is a method for producing a trisulfide compound or a selenotrisulfide compound. This production method includes: a step for oxidizing a disulfide compound with an oxidizing agent to obtain a sulfoxide compound; and a step for reacting the sulfoxide compound that has been obtained with a source of sulfur or a source of selenium to obtain a trisulfide compound or a selenotrisulfide compound.

Disclosed is a method for producing a trisulfide compound or a selenotrisulfide compound. This production method includes: a step for oxidizing a disulfide compound with an oxidizing agent to obtain a sulfoxide compound; and a step for reacting the sulfoxide compound that has been obtained with a source of sulfur or a source of selenium to obtain a trisulfide compound or a selenotrisulfide compound.

The present invention relates to a novel use of magnetic iron oxide red Fe.sub.21.333O.sub.32 as a catalyst in oxidizing methanthiol to prepare dimethyl disulfide. The magnetic iron oxide red Fe.sub.21.333O.sub.32 according to the present invention has extremely high catalytic selectivity in catalyzing and oxidizing methanthiol to prepare dimethyl disulfide. The magnetic iron oxide red Fe.sub.21.333O.sub.32 is prepared with a carbonate and a ferrite as raw materials, has advantages of low cost and simple preparation process, and is suitable for industrial production.

The present invention relates to a novel use of magnetic iron oxide red Fe.sub.21.333O.sub.32 as a catalyst in oxidizing methanthiol to prepare dimethyl disulfide. The magnetic iron oxide red Fe.sub.21.333O.sub.32 according to the present invention has extremely high catalytic selectivity in catalyzing and oxidizing methanthiol to prepare dimethyl disulfide. The magnetic iron oxide red Fe.sub.21.333O.sub.32 is prepared with a carbonate and a ferrite as raw materials, has advantages of low cost and simple preparation process, and is suitable for industrial production.

The present invention relates to a novel use of magnetic iron oxide red Fe.sub.21.333O.sub.32 as a catalyst in oxidizing methanthiol to prepare dimethyl disulfide. The magnetic iron oxide red Fe.sub.21.333O.sub.32 according to the present invention has extremely high catalytic selectivity in catalyzing and oxidizing methanthiol to prepare dimethyl disulfide. The magnetic iron oxide red Fe.sub.21.333O.sub.32 is prepared with a carbonate and a ferrite as raw materials, has advantages of low cost and simple preparation process, and is suitable for industrial production.

According to the present invention, there is provided a method of producing a salt, including reacting M.sup.+X.sup.− with YH to generate XH and M.sup.+Y.sup.− and subsequently removing the generated XH to obtain the M.sup.+Y.sup.−.

In the method of producing a salt, M.sup.+X.sup.− is a salt of a cation represented by M.sup.+ and an anion represented by X.sup.−, M.sup.+Y.sup.− is a salt of the cation represented by M.sup.+ and an anion represented by Y.sup.−, XH is a conjugate acid of X.sup.−, YH is a conjugate acid of Y.sup.−, M.sup.+Y.sup.− is a compound that generates an acid upon irradiation with an active ray or a radioactive ray, a pKa of XH is larger than a pKa of YH, and a ClogP value of XH is larger than 2.

According to the present invention, there is provided a method of producing a salt, including reacting M.sup.+X.sup.− with YH to generate XH and M.sup.+Y.sup.− and subsequently removing the generated XH to obtain the M.sup.+Y.sup.−.

In the method of producing a salt, M.sup.+X.sup.− is a salt of a cation represented by M.sup.+ and an anion represented by X.sup.−, M.sup.+Y.sup.− is a salt of the cation represented by M.sup.+ and an anion represented by Y.sup.−, XH is a conjugate acid of X.sup.−, YH is a conjugate acid of Y.sup.−, M.sup.+Y.sup.− is a compound that generates an acid upon irradiation with an active ray or a radioactive ray, a pKa of XH is larger than a pKa of YH, and a ClogP value of XH is larger than 2.

The present invention includes pharmaceutical composition comprising (2R,2R′)-3,3′-disulfanediyl bis(2-acetamidopropanamide)(diNACA) or D.sub.3-N-acetyl cysteine amide, or a physiologically acceptable salt thereof, having a deuterium enrichment above the natural abundance of deuterium, and derivatives or solids thereof, and methods of using diNACA to treat eye diseases and other diseases associated with oxidative damage including, e.g., antivenom, beta-thallassemia, cataract, chronic obstructive pulmonary disease, macular degeneration, contrast-induced nephropathy, asthma, lung contusion, methamphetamine-induced oxidative stress, multiple sclerosis, Parkinson's disease, platelet apoptosis, Tardive dyskinesia, Alzheimer disease, HIV-1-associated dementia, mitochondrial diseases, myocardial myopathy, neurodegenerative diseases, pulmonary fibrosis, skin pigmentation, skin in need of rejuventation, antimicrobial infection, Friedreich's ataxia.