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Magnetostriction of Fe1−xCox (x = 50–90 at%) alloys prepared by forging and subsequent cold-rolling was studied as functions of alloy compositions and thermomechanical treatments. Magnetostriction of the as-forged Fe25Co75 alloy was 108 ppm and that of the as-cold rolled Fe25Co75 alloy measured parallel to the rolling direction (RD) was 128 ppm. The cold-rolled Fe25Co75 alloy possessed a nearly {1 0 0} texture, leading to the maximum magnetostriction of 140 ppm when measured at an angle of 45° to RD. Moreover, the fully annealed Fe25Co75 and Fe20Co80 alloys were gradually cold rolled and magnetostriction were measured. Results showed that the magnetostriction of those cold-rolled alloys drastically increased with increasing reduction rate. According to the XRD and TEM observations, intensity of the fcc peak gradually decreased with increasing reduction rate and that the alloys became to be in a bcc single state at a reduction rate higher than 90%, leading to a drastic increase in magnetostriction.

The synthesis of bestatin (1), based on the regio-selective introduction of a nitrogen function to a non-protected diol 9, is described.

Lead (Pb) is one of the most effective alloying elements to improve the machinability of steels. However the movement of eliminating Pb contents is recently increasing because of reducing environmental impact. Therefore new types of free cutting steels without Pb are strongly required. Ti4C2S2 is one of the promissing candidates of free cutting elements. However the mechanism of improvement in machinability by Ti4C2S2 has not been confirmed yet. In this study we investgated the effect of Ti4C2S2 in 13 % Cr stainless steels. Ti4C2S2 had notch effect like other sulfides such as MnS. Thereby chip breakability was improved. Ti4C2S2 also had tool-protecting effect by forming stable adhesion. On the other hand Ti4C2S2 was not shown remarkable lubricant effect as Pb. The improvement of machinability in 13 mass%Cr ferritic stainless steels by including Ti4C2S2 attribute to the chip breakability and restraint of the tool-wear by forming stable adhesion.

Although conventional free-cutting soft-magnetic stainless steel contains Pb to facilitate machining, the replacement and elimination of Pb is required from the standpoint of environmental protection. In this article, the authors report the development of new Pb-free machinable soft-magnetic stainless steels in which titanium carbo-sulfide is used as an inclusion. The microstructural evolution, magnetic properties, corrosion resistance, machinability and mechanical properties of these new free-cutting stainless steels are presented.

Voices of our customers in late 1990s requiring soft-magnetic steels with high hardness for high wear resistance and high durability drove us to launch research and development and we have succeeded in developing a new steel K-M57, Fe-15Cr based precipitation-hardened ferritic steel by modifying a base steel with high hardness above 400HV but not quite satisfactory concerning magnetic properties and manufacturability. A simple relationship between concentrations of alloy elements and matrix phase has been found around the composition of base steel which gave us a confirmation about stability of ferritic matrix and helped us to design the new steel. Newly developed K-M57 has both high hardness (>350HV) and high performance soft-magnetic properties (Hc2500μH/m, B2000>1.2Tesla) simultaneously, which satisfy the requirements of magnetic cores of various types of solenoid valves including fuel injectors of automobiles. It also has high corrosion resistance and high electric resistivity (ρ≅90μΩ-cm) suitable for highly responsive devices. K-M57 has also good manufacturability due to low hardness ( It is expected that the demands for the new steel will further extend because of its potential for expanding freedom of solenoids' design and eliminating surface hardening treatment of parts as well as of eco-friendliness from them.

A new sesquiterpene, (1 S ,2 S ,6 R ,8 R )-1-isopropyl-5-(hydroxymethyl)-8-methyltricyclo[4.4.0.0 2,R ]dec-4-ene ( 1 ), was isolated and identified from the leaf surface lipids of Nicotiana umbratica Burbidge. The structure of compound 1 , including the absolute stereochemistry, was established on the basis of its spectral data and X-ray diffraction analysis of 15- p -bromobenzoate ( 1a ).

Phytosphingosine, (2S,3S,4R)-2-amino-1,3,4-octadecanetriol was prepared in 8.6% overall yield in 17 steps from levoglucosenone (1,6-anhydro-3,4-dideoxy-β- d -glycero-hex-3-enopyranos-2-ulose) by reduction of the carbonyl group, selective cis-oxyamination of the carbon-carbon double bond, oxidation of the 2-hydroxyl group to the carbonyl group, regioselective Baeyer-Villiger oxidation, reduction of the afforded lactone to the linear amino alcohol, oxidation of the primary hydroxyl group to the aldehyde, introduction of the hydrocarbon chain using a Wittig reaction, hydrogenation of the resulting carbon-carbon double bond, and deprotection.

2,3-Dideoxy-2-fluoro-D-erythro-pentofuranose was easily prepared from 3-DPA lactone. The condensation reaction between 1-O-acetyl derivative of this sugar and silylated thymine in the presence of TMSOTf proceeded in a poorly stereoselective manner.

Two rare amino sugars, 3-acetamido-3-deoxy- and 4-acetamido-4-deoxy- d -altrose, were prepared from levoglucosenone (1,6-anhydro-3,4-dideoxy-β- d - glycero -hex-3-enopyranos-2-ulose) respectively by reduction of the carbonyl group, selective cis -oxyamination of the carbon-carbon double bond, detosylation of the p -toluenesulfonamido group, acetylation, acetolysis of the 1,6-anhydro bond, and finally deacetylation of the O -acetyl groups. The regioselectivity in cis -oxyamination of the carbon-carbon double bond of allylic alcohol obtained by reduction of levoglucosenone could be controlled by the choice of the protecting groups of the allylic hydroxyl group.

Levoglucosenone [1, 6-anhydro-3, 4-dideoxy-β-D-glycero-hex-3-eno-pyrano-2-ulose, (4)] is widely known as a pyrolytic product of cellulose. It is very useful chiral source for synthesizing natural products owing to its highly functionalized structure containing essentially one chiral center. The synthesis of useful compounds starting from levoglucosenone (4) and their applications as useful chiral building blocks are reviewed in this article.

The pheromones (1a,1b) of two insect pests, the Japanese Beetle (Popillia japonica, Newman) and Cupreus Chafer Beetle (Anomala cuprea, Hope), were synthesized. Starting from protected D-Ribose, 1a was prepared in 8 steps with a 30% total yield. The same chemistry was demonstrated for the synthesis of 1b.

(+)-Grandisol, which is a component of the male-produced pheromone of the boll weevil, Anthonomus grandis, was synthesized from levoglucosenone. The key steps in the synthesis are the intramolecular diatereoselective four-membered ring construction and the Baeyer-Villiger oxidation. The 17-step procedure led to a known synthetic intermediate of (+)-grandisol.

Coupling reactions between 1-chloro-2,3-dideoxyribose and silylated pyrimidines have been examined from the point of stereoselectivity. When the reaction was carried out in chloroform, the selectivity was in the anomeric ratio of α:β=4:6. On the other hand, the presence of tertiary amine raises the selectivity to α:β=3:7

Coupling reaction between 2-α-phenylthio-2,3-dideoxyribose and silylated pyrimidine bases in the presence of SnCl4 proceeded stereoselectively to give the β-anomers. These nucleosides were converted to 2′,3′-dideoxy-2′,3′-didehydronucleosides by oxidation followed by thermal elimination.

Stereoselectivities in coupling reactions between silylated pyrimidine bases and 3- or 2-α-phenylthio-2,3-dideoxyribose were examined. In the former case, no stereoselectivities were observed when the coupling reactions were performed either with 1-chlorosugar in an S N 2 mode or in the presence of Lewis acids as catalyst in an S N 1 mode. Coupling reaction with 2-α-phenylthio-2,3-dideoxyribose in the presence of Lewis acids, especially SnCl 4 , proceeded with good stereoselectivity to give anomeric mixtures of α:β=1:9. All these nucleosides were converted to 2',3'-didehydro-2',3'-dideoxynucleosides by oxidation to sulfoxides followed by thermal elimination of sulfenic acid

Many nucleoside analogues, which lack 2'-substituents, have been known to be a useful compound as anticancer and anti-virus agents. On the other hand, synthesis of these derivatives utilizing the condensation reactions between sugars and nucleic bases have a difficulty in the stereoselectivity of these reactions. In this paper, our investigation on the condensation reactions with some 2-deoxysugars are discussed in the point of stereoselectivity. Transformations to 2', 3'-dideoxynucleosides and 2', 3'-didehydro-2', 3'-dideoxynucleosides are also described.

Reaction of furanoid glycals with PhSCl afforded 1-chlorosugars, which were used for condensation reaction with silylated uracil in the presence of SnCl4. These two reactions proceeded in a highly stereoselective manner

The pheromones (1a,1b) of two insect pests, the Japanese Beetle (Popillia japonica, Newman) and Cupreus Chafer Beetle (Anomala cuprea, Hope), were synthesized. Starting from protected D-Ribose, 1a was prepared in 8 steps with a 30% total yield. The same chemistry was demonstrated for the synthesis of 1b.

Furanoid glycal was utilized as a starting material for the nucleoside derivatives with the aid of benzenesulfenyl chloride. Condensation reaction with silylated nucleic bases was high in the presence of SnCl 4 . Electrophilic addition of benzenesulfenyl chloride to the glycal with substituent also proceeded in high stereoselectivity. Phenylthio-substituted nucleoside was used to convert 2',3'-dideoxynucleoside and 2',3'-didehydro-2',3'-dideoxynucleoside

2,3-Dideoxy-2-fluoro-D-erythro-pentofuranose was easily prepared from 3-DPA lactone. The condensation reaction between 1-O-acetyl derivative of this sugar and silylated thymine in the presence of TMSOTf proceeded in a poorly stereoselective manner.

Two lactones, (3S,4R)- and (3R,4R)-3-hydroxy-4-hydroxymethyl-4-butanolides, were easily and stereoselectively synthesized in good yield from levoglucosenone (1,6-anhydro-3,4-dideoxy-β-D-glycero-hex-3-enopyranos-2-ulose).

Two rare amino sugars, 3-acetamido-3-deoxy- and 4-acetamido-4-deoxy- d -altrose, were prepared from levoglucosenone (1,6-anhydro-3,4-dideoxy-β- d - glycero -hex-3-enopyranos-2-ulose) respectively by reduction of the carbonyl group, selective cis -oxyamination of the carbon-carbon double bond, detosylation of the p -toluenesulfonamido group, acetylation, acetolysis of the 1,6-anhydro bond, and finally deacetylation of the O -acetyl groups. The regioselectivity in cis -oxyamination of the carbon-carbon double bond of allylic alcohol obtained by reduction of levoglucosenone could be controlled by the choice of the protecting groups of the allylic hydroxyl group.

Phytosphingosine, (2S,3S,4R)-2-amino-1,3,4-octadecanetriol was prepared in 8.6% overall yield in 17 steps from levoglucosenone (1,6-anhydro-3,4-dideoxy-β- d -glycero-hex-3-enopyranos-2-ulose) by reduction of the carbonyl group, selective cis-oxyamination of the carbon-carbon double bond, oxidation of the 2-hydroxyl group to the carbonyl group, regioselective Baeyer-Villiger oxidation, reduction of the afforded lactone to the linear amino alcohol, oxidation of the primary hydroxyl group to the aldehyde, introduction of the hydrocarbon chain using a Wittig reaction, hydrogenation of the resulting carbon-carbon double bond, and deprotection.

A new sesquiterpene, (1 S ,2 S ,6 R ,8 R )-1-isopropyl-5-(hydroxymethyl)-8-methyltricyclo[4.4.0.0 2,R ]dec-4-ene ( 1 ), was isolated and identified from the leaf surface lipids of Nicotiana umbratica Burbidge. The structure of compound 1 , including the absolute stereochemistry, was established on the basis of its spectral data and X-ray diffraction analysis of 15- p -bromobenzoate ( 1a ).

Synthesis of CMP-deaminoneuraminic acid (CMP-β- d -Kdn) and its enzymatic transfer reaction using bacterial α-(2→6)-sialyltransferase were examined. CMP-β- d -Kdn was prepared from methyl 4,5,7,8,9-penta- O -acetyl-3-deoxy- d - glycero -β- d - galacto -2-nonulopyranosonate ( 2 ) in 24% overall yield. Enzymatic synthesis of Kdn oligosaccharide with CMP-β- d -Kdn (10.2 μmol), methyl β- d -lactosaminide ( 7 , 8.1 μmol) and purified sialyltransferase (80 munits) afforded Kdn-α-(2→6)-Gal-β-(1→4)-GlcNAc-β-1-OMe in 77% yield.

The condensation reaction between 2,2-diphenylthio-2,3-dideoxyribose and silylated pyrimidine bases was examined. In the presence of TMSOTf as a catalyst, this reaction proceeded to give the nucleosides in the ratio of α: β = 2:8. Each β-anomer was converted to protected 2′,3′-dideoxynucleosides.

Many nucleoside analogues, which lack 2'-substituents, have been known to be a useful compound as anticancer and anti-virus agents. On the other hand, synthesis of these derivatives utilizing the condensation reactions between sugars and nucleic bases have a difficulty in the stereoselectivity of these reactions. In this paper, our investigation on the condensation reactions with some 2-deoxysugars are discussed in the point of stereoselectivity. Transformations to 2', 3'-dideoxynucleosides and 2', 3'-didehydro-2', 3'-dideoxynucleosides are also described.

(2E,4E)-geometry was assigned to 1233A [(7R,2ʹR,3ʹR)-11-[3ʹ-(hydroxymethyl)-4ʹ-oxo-2ʹ-oxetanoyl]-3,5,7-trimethyl-2,4-undecadienoic acid (1a)], an inhibitor of cholesterol biosynthesis. Both the 1H- and 13C-NMR spectra of 1a and methyl ester 1b were compared with those of the four geometrical isomers of methyl 3,5-dimethyl-2,4-heptadienoate (2). NOE experiments on 1b revealed the presence of a remarkable NOE between the proton at C-2 and those of the C-17 methyl group. Similar NOE was also observed with (2E,4E)-2. This fact suggests the predominant existence of stable s-cis-rotamers at the single bond between C-3 and C-4 of 1b and of (2E,4E)-2. Some MM2 calculations were attempted to show the presence of two types of stable conformers in the case of the 3,5-dimethyl-2,4-dienoate system.

Coupling reaction between 2-α-phenylthio-2,3-dideoxyribose and silylated pyrimidine bases in the presence of SnCl4 proceeded stereoselectively to give the β-anomers. These nucleosides were converted to 2′,3′-dideoxy-2′,3′-didehydronucleosides by oxidation followed by thermal elimination.

1′-Epi-stegobinone [(2S,3R,1′S)-2,3-dihydro-2,3,5-trimethyl-6-(1′-methyl-2′-oxobutyl)-4H-pyran-4-one], an inhibitor of stegobinone, which is the sex pheromone of drugstore beetle (Stegobium paniceum L.), was synthesized by stereocontrol at C-2 and C-1′ starting from ethyl (R)-3-hydroxybutanoate and methyl (R)-3-hydroxypentanoate.

2′,3′-Didehydro-2′,3′-dideoxy nucleosides were synthesized from 2′,2′-bis(phenylthio) nucleoside analogs via five-step reactions. The sulfonyl group of the intermediate was removed by a treatment with sodium amalgam.

Two lactones, (3S,4R)- and (3R,4R)-3-hydroxy-4-hydroxymethyl-4-butanolides, were easily and stereoselectively synthesized in good yield from levoglucosenone (1,6-anhydro-3,4-dideoxy-β-D-glycero-hex-3-enopyranos-2-ulose).

Synthesis of CMP-deaminoneuraminic acid (CMP-beta-D-Kdn) and its enzymatic transfer reaction using bacterial alpha-(2--6)-sialyltransferase were examined. CMP-beta-D-Kdn was prepared from methyl 4,5,7,8,9-penta-O-acetyl-3-deoxy-D-glycero-beta-D-galacto-2- nonulopyranosonate (2) in 24% overall yield. Enzymatic synthesis of Kdn oligosaccharide with CMP-beta-D-Kdn (10.2 mumol), methyl beta-D-lactosaminide (7, 8.1 mumol) and purified sialyltransferase (80 munits) afforded Kdn-alpha-(2--6)-Gal-beta-(1--4)-GlcNAc-beta-1-OMe in 77% yield.

A novel immobilization procedure for glycoproteins is based on the reacion of immobilized CMP-NeuAc (CMP-sialic acids) with sialyltransferase (see scheme). The transfer ability was tested under various conditions; a corresponding oligosaccharide or asialoglycoprotein acted as sialyl acceptor. The solid-phase synthesis of CMP-NeuAc is also described.