- Development of Odorless Thiols and Sulfides and Their Applications to Organic Synthesis
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Development of new odorless thiols (dodecanethiol, 4-n- heptylphenylmethanethiol, 4-trimethylsilylphenylmethanethiol, 4-trimethylsilylbenzenethiol) and an odorless sulfide (1-methylsulfanyldodecane) and their applications to dealkylation, Michael addition, Swern oxidation, and Corey-Kim oxidation are described.
- Nishide, Kiyoharu,Ohsugi, Shin-Ichi,Miyamoto, Tetsuo,Kumar, Kamal,Node, Manabu
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p. 189 - 200
(2007/10/03)
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- Odorless substitutes for foul-smelling thiols: Syntheses and applications
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Several alkanethiols and p-alkylphenylmethanethiols were synthesized, and their odors were compared with those of ethanethiol and benzyl mercaptan by human and instrumental sensors. Among the various thiols analyzed, 1-dodecanethiol (1) and p-heptylphenylmethanethiol (3) were revealed to be odorless. 1-Dodecanethiol (1) has been used instead of ethanethiol for dealkylation of ethers, and p-heptylphenylmethanethiol (3) can replace benzyl mercaptan in the preparation of a 1,3-mercapto alcohol from an α,β-unsaturated ketone. These odorless thiols will greatly improve the physical environment of the researcher working with these foul-smelling compounds.
- Node, Manabu,Kumar, Kamal,Nishide, Kiyoharu,Ohsugi, Shin-Ichi,Miyamoto, Tetsuo
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p. 9207 - 9210
(2007/10/03)
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- New reagent for the optical resolution of ketones: (-) (1R, 2R, 5R)-5-methyl-2-(1-mercapto-1-methylethyl)-cyclohexanol. Application to trans dimethyl cyclopentanone-3,4-dicarboxylate
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(-) (1R, 2R, 5R)-5-methyl-2-(1-mercapto-1-methylethyl)-cyclohexanol was shown to be a very powerful agent for the optical resolution of ketones. It was used for the resolution of trans dimethyl cyclopentanone-3,4-dicarboxylate combined with the epimerizat
- Solladie,Lohse
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p. 1547 - 1552
(2007/10/02)
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- ASYMMETRIC SYNTHESES BASED ON HEXAHYDRO-4,4,7-TRIMETHYL-1,3-BENZOXATHIANS
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Earlier work concerned with a highly stereoselective asymmetric synthesis based on a 1,3-oxathiane as the chiral auxiliary reagent is reviewed and recent applications to the synthesis of the four stereoisomers of malyngolide, of (R)-(+)-γ-caprolactone (a
- Eliel, Ernest L.
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- Asymmetric Syntheses Based on 1,3-Oxathianes. 2. Synthesis of Chiral Tertiary α-Hydroxy Aldehydes, α-Hydroxy Acids, Glycols (RR'C(OH)CH2OH), and Carbinols (RR'C(OH)CH3) in High Enantiomeric Purity
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A chiral 1,3-oxathiane (5) prepared from (+)-pulegone in three steps is converted to diastereomerically pure equatorial 2-acyl derivatives by lithiation, condensation with aldehydes, and Me2SO oxidation.Reaction of the resulting ketones with Grignard reagents at -78 deg C again proceeds highly stereoselectively (diastereomer excess generally above 90percent) according to Cram's rule (cyclic model).The resulting tertiary carbinols when cleaved with NCS/AgNO3 give chiral tertiary α-hydroxy aldehydes, RR'C(OH)CHO, plus a mixture of epimeric sultines which may be readily reconverted to the starting oxathiane.The hydroxy aldehydes have been oxidized to chiral tertiary α-hydroxy acids, RR'C(OH)CO2H, and reduced to primary-tertiary glycols, RR'C(OH)CH2OH, and further to tertiary carbinols, RR'C(OH)CH3, all with over 90percent ee.The opposite enantiomers of these compounds (again >90percent ee) may be obtained by starting with a diastereomeric 1,3-oxathiane (6), also available from (+)-pulegone.The configurations of the chiral products may be deduced from the manner of preparation and the assumption that Cram's rule is valid and agree with prior assignments in the literature.
- Lynch, Joseph E.,Eliel, Ernest L.
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p. 2943 - 2948
(2007/10/02)
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- ASYMMETRIC SYNTHESIS OF (R)-(+)-ETHYLMETHYL-n-PROPYLCARBINOL IN HIGH ENANTIOMERIC PURITY. A 1,3-OXATHIANE DERIVED FROM (+)-PULEGONE AS CHIRAL ADJUVANT
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A chiral, conformationally locked 1,3-oxathiane has been prepared by 1,4-addition of benzyl mercaptan to (+)-pulegone followed by Na/NH3 reduction and condensation of the resulting hydroxythiol with paraformaldehyde.The utility of this chiral adjuvant is
- Eliel, Ernest L.,Lynch, Joseph E.,Kenan, William R. Jr.
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p. 2855 - 2858
(2007/10/02)
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