Abstract: Provided is free cutting alloy excellent in machinability, preserving various characteristics as alloy. The free cutting alloy contains: one or more of Ti and Zr as a metal element component; and C being an indispensable element as a bonding component with the metal element component, wherein a (Ti, Zr) based compound including one or more of S, Se and Te is formed in a matrix metal phase. The free cutting alloy is more excellent in machinability, preserving various characteristics as alloy at similar levels to a conventional case. The effect is especially conspicuous, for example, when a compound expressed in a chemical form of (Ti, Zr)4C2(S, Se, Te)2 as the (Ti, Zr) based compound is formed at least in a dispersed state in the alloy structure.

Abstract: Disclosed is a corrosion resistant steel having good machinability with sufficient corrosion resistance in the ordinary indoor circumstances and suitable for manufacturing shafts of various small motors and OA-machines. The steel comprises, by weight %, C: 0.005-0.200%, P: up to 0.05%, Cu: up to 2.0%, Ni: up to 2.0%, Cr: 2.0-9.0%, one or both of Ti and Zr: in such an amount as [Ti%]+0.52[Zr%]: 0.03-1.20%, one or both of S: 0.01-0.50% and Se: 0.01-0.40%, N: up to 0.050% and O: up to 0.030%, the balance being Fe and inevitable impurities. The steel is characterized by the inclusion therein, which are Ti-based, Zr-based or Ti—Zr-based compound or compounds containing C and one or both of S and Se.

Abstract: A free-cutting Ni-base heat-resistant alloy excellent in the high-temperature strength and corrosion resistance was proposed. The alloy contains Ni as a major component, 0.01 to 0.3 wt % of C and 14 to 35 wt % of Cr, and further contains at least one element selected from Ti, Zr and Hf in a total amount of 0.1 to 6 wt %, and S in an amount of 0.015 to 0.5 wt %. The alloy has dispersed in the matrix thereof a machinability improving compound phase, where such phase contains any one of Ti, Zr and Hf as a major constituent of the metal elements, essentially contains C and either S or Se as a binding component for such metal elements. The alloy also satisfies the relations of WTi+0.53WZr+0.27WHf>2WC+0.75WS and WC>0.37WS, where WTi represents Ti content (wt %), WZr represents Zr content (wt %), WHf represents Hf content (wt %), WC represents C content (wt %) and WS represents S content (wt %).

Abstract: The present invention is drawn to methods of manufacturing a sialic acid derivative suitable for industrial production. With a method of the present invention, Tetra-O-acetylsialic acid (4a) and acetylcytidine-5'-O-amidite (5a) are condensed in the presence of an acid catalyst to obtain a phosphite (6a). The phosphite (6a) is oxidized with t-butylhydroperoxide to obtain a phosphate (9a). The phosphate (9a) is deprotected with an alkali to obtain CMP-sialic acid (1a). ##STR1## The present invention further encompasses a novel sialic acid derivative.

Abstract: After the lactone portion of trans-whiskey lactone is hydrolyzed with potassium hydroxide, this portion is reacted with isopropyl bromide and mixed with an alkyl group, thereby obtaining isopropyl (3S,4S)-4-hydroxy-3-methyloctanoate. Then, the isopropyl (3S,4S)-4-hydroxy-3-methyloctanoate is reacted with diethyl azodicarboxylate in the presence of triphenylphosphine and azodicarboxylate, thereby obtaining isopropyl (3S,4S)-4-(3',5'-dinitrobenzoyloxy)-3-methyloctanoate. The isopropyl (3S,4S)-4-(3',5'-dinitrobenzoyloxy)-3-methyloctanoate is hydrolyzed in 2% potassium hydroxide, and as a result, cis-whiskey lactone (A) represented by the following general formula is obtained. According to this method, cis-whiskey lactone, one of the perfume components of whiskey and wine, can be produced selectively and easily.

Abstract: The carbonyl group at the 2-position of levoglucosenone is reduced to obtain a hydroxyl group having a .beta.-configuration. The hydroxyl group having a .beta.-configuration is reversed to an .alpha.-configuration, and hydroxyl groups are added at the 3- and 4-positions in a cis-.alpha. form. Finally, the protective group of the hydroxyl group at the 2-position is eliminated. The reduction of the carbonyl group at the 2-position can be performed such that the levoglucosenone is reacted with aluminum lithium hydride or sodium boron hydride in an appropriate solvent. Reversion of the hydroxyl group having a .beta.-configuration can be performed by the Mitsunobu method or a method having a mesylation step and a step using cesium acetate. The addition of the hydroxyl groups to the 3-and 4-positions in the cis form can be performed by oxidizing the double bond across the 3- and 4-positions with an appropriate oxidizing agent.

Abstract: There is provided a method of preparing an epoxide (1a) or (1b) shown below: ##STR1## where R.sup.1, R.sup.2, R.sup.3, and R.sup.4 represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an aryloxy group, an acyl group, an alkyloxycarbonyl group, an aryloxycarbonyl group, allalkyl group, a silyl group, and a silyloxy group; the groups may be bonded with each other to form rings in the case where these groups can be bivalent; these groups may be the same or different, may have substituting groups, or may be branched; and each form (isomer) has a structure in which one side of the plane constituted by double bonds, R.sup.1, R.sup.2, R.sup.3 and R.sup.4, is more seterically hindered in comparison with the other side;characterized in that:an olefin represented by the formula (2) below, is reacted with iodine in the presence of compound generating acyloxy ion, ##STR2## where R.sup.1, R.sup.2, R.sup.3 and R.sup.

Abstract: 2,3-Dideoxy-2,2-di(organothio)-B-D-pentofuranosyl-pyrimidines are disclosed as intermediates in the synthesis of 2', 3'-dideoxynucleosides and have the structure shown below. ##STR1## wherein R.sup.4 is a hydroxyl protecting group;X is oxygen or nitrogen, said nitrogen being bonded to a hydrogen atom, an alkyl or acyl group;Y is hydrogen, halogen, alkyl, haloalkyl or haloalkenyl; andR.sup.5 is alkyl, aralkyl, or aryl wherein aralkkyl or aryl is substituted with hydrogen, halogen, nitro or alkoxy.2', 3'-Dideoxynucleosides, products of the above intermediates, are useful as antiviral agents.

Abstract: Providing a method of preparing (3R,4R)-3-hydroxy-4-hydroxymethyl-4-butanolide conveniently and selectively from a widely available raw material in a high yield. A carbonyl group of the 2-position of levoglucosenone is reduced to obtain a hydroxyl group of a .beta.-configuration. Then, an iodo-group of an .alpha.-configuration and an acyloxy ion of a .beta.-configuration are introduced regioselectively and stereoselectively to the double bond at the 4-position and the 3-position of the above-mentioned levoglucosenone, respectively, keeping a trans stereochemical relationship. An alkoxide is then formed, by hydrolysis and an oxirane ring of a .beta.-configuration is formed by removing an iodo-group by intramolecular nucleophilic displacement reaction of the alkoxide.

Abstract: Disclosed is a method of preparing D-altrose (4) from the starting material levo-glucosenon (1) in accordance with reactions denoted by reaction formulas (I), (II) and (III) given below: ##STR1##

Abstract: The present invention discloses a method of preparing 3-DPA-lactone, which is difficult to obtain in a large amount from nature. According to the method of the present invention, the target compound can be synthesized at a high yield in fewer steps and more easily than by the conventional synthesizing technique, and selectively from a widely available material. In the method of the present invention, the hydroxyl groups at the 2- and 5 -positions of .gamma.-ribonolactone are protected, and then the hydroxyl group at the 3-position is eliminated so as to form a double bond between the 2- and 3-positions. After that, the protecting groups for the hydroxyl groups are eliminated.

Abstract: An alkynyl group having a triple bond at the carbon atom at the 1-position is introduced to a carbon atom at the 1-position of 2,3-O-isopropylidene-D-ribofuranose. The diol part is then cleaved to obtain a lactol compound. This lactol compound is oxidized to obtain a lactone compound. The ketal part of the lactone compound is hydrolyzed and the compound is further subjected to a reduction reaction. The hydroxyl groups at the 2- and 3-positions are then eliminated, and the double bond between the 2- and 3-positions of the resultant compound is reduced to obtain a 4-substituted-.gamma.-lactone.

Abstract: In the method of the present invention for manufacturing 3-DPA-lactone, a protective group is introduced in the first step into the hydroxyl group at 4-position of .gamma.-ribonolactone by an ordinary method. Then, an acid anhydride or an acid chloride is added in the presence of a tertiary amine compound so as to conduct a .beta.-elimination of the hydroxyl group at the 3-position. As a result, a double bond is formed between the 2- and 3-positions and, at the same time, the hydroxyl group at the 2-position is acylated. The double bond between the 2- and 3-positions is reduced in the next step by means of a catalytic hydrogenation. Finally, the protective group of the hydroxyl group is eliminated by an ordinary method. The particular method permits using readily available raw materials, decreasing the number of manufacturing steps, and easily and selectively synthesizing the desired 3-DPA-lactone, which is hardly obtained from nature in a large amount, in high yield, compared with the conventional method.

Abstract: A method for producing (R,Z)-5-tetradecen-4-olide, comprising the following reaction formulas; ##STR1##

Abstract: An acid addition salt of .delta.-aminolevulinic acid is prepared in such a way that tetrahydrofurfurylamine (VI) is reacted with phthalic anhydride under an anhydrous condition to introduce a phthal group which protects amino group of tetrahydrofurfurylamine to give N-tetrahydrofurfuryl phthalimide (III), carbon atoms of the first- and fourth-positions of thus obtained N-tetrahydrofurfurylphthalimide (III) are oxidized at 80.degree. C. using sodium periodate as a oxidizing agent and ruthenium chloride hydrate as a catalyst to yield 5-phthalimidolevulinic acid (II), then the protecting group of 5-phthalimidolevulinic acid (II) is deprotected using an acid to prepare an acid additional salt of .delta.-aminolevulinic acid. The acid additional salt of .delta.-aminolevulinic acid is readily converted by neutralization by an alkali to .delta.-aminolevulinic acid, which is very useful as a precursor of Vitamin B.sub.12, heme and chlorophyll.

Abstract: The instant invention is drawn to a method for manufacturing 2',3'-dideoxy-2',3'-didehydronucleoside compounds by reacting a ribonucleoside derivative wherein the hydroxyl in the 5'-position of the furanose ring of said ribonucleoside is protected by a silyl protective group, with an acid anhydride such as acetic anhydride in the presence of a catalyst such as hydrous zirconium oxide, and then subjecting the reaction product to decarboxylation. The decarboxylation can be effected by heating the reaction product. This method can be performed in a single step, and requires no reagents which are expensive or chemicals which should be handled with care. Hence, it serves to manufacture 2',3'-dideoxy-2',3'-didehydronucleosides easily at low cost.

Abstract: First, levoglucosenone is made to react with methyl lithium in the presence of copper iodide in order to introduce a methyl group into an enone group of levoglucosenone, and to obtain 1,6-anhydro-3,4-dideoxy-4-C-methyl-.beta.-D-erythro-hexopyranose-2-ulose. This methyl compound is oxidized in acetic acid for lactone formation, and (3S,4S)-5-hydroxy-3-methylpentan-4-olide is thus obtained. Further, this lactone is made to react with tosyl chloride in anhydrous pyridine to obtain (3S,4S)-3-methyl-5-tosyloxypentan-4-olide (tosylate). The obtained tosylate is alkylated with n-propyl lithium in the presence of copper iodide to obtain (3S,4R)-3-methyl-4-octanolide. Here, the (3S,4S)-3-methyl-5-tosyloxypentan-4-olide may be treated with potassium carbonate to cleave lactone ring once, thereby obtaining epoxide. After that, the obtained epoxide is alkylated to form lactone ring again to obtain (3S,4R)-3-methyl-4-octanolide.

Abstract: (S)-4-hydroxymethyl-.gamma.-lactone is prepared by oxidizing dihydrolevoglucosenone with a peracid in an organic solvent. (S)-4-hydroxymethyl-.gamma.-lactone is prepared from levoglucosenone. First, levoglucosenone is catalytic hydrogenated, thereby dihydrolevoglucosenone is obtained. Next, dihydrolevoglucosenone thus obtained is oxidized with a peracid in an organic solvent, thereby (S)-4-hydroxymethyl-.gamma.-lactone is obtained. In this manner, (S)-4-hydroxymethyl-.gamma.-lactone can be obtained with high optical purity.

Abstract: The present invention is a process for preparing 2'-deoxy-5-trifluoromethyl-.beta.uridine characterized in that a 5-trifluoromethyl-2,4-bis(triorganosilyloxy)pyrimidine and a 1-halogeno-2-deoxy-.alpha.-D-erythro-pentofuranose derivative are subjected to condensation reaction in chloroform to give a 1-(2-deoxy-.beta.-D-erythro-pentofuranoxyl)-5-trifluoromethyluracil derivative which is then subjected to the deprotection reaction to give 2'-deoxy-5-trifluoromethyl-.beta.-uridine.

Abstract: A method of preparing (S)-.gamma.-hydroxymethyl-.alpha.,.beta.-butenolide includes the step of oxidizing a levoglucosenone with a peracid in an organic solvent. Peracetic acid, metha-chloroperbenzoic acid or magnesium monoperoxyphthalate hexahydrate can be used as the peracid. According to this method, an (S)-.gamma.-hydroxymethyl-.alpha.,.beta.-butenolide having high optical purity can be easily prepared from a levoglucosenone as a starting material at a high yield.