- Lipase-mediated resolution of indene bromohydrin
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Lipase-mediated resolution of indene bromohydrin was examined, and we have found that immobilized CAL (Candida antarctica lipase SP525 immobilized on acurrell) was an efficient biocatalyst to resolve a readily available racemic indene bromohydrin (+)-1. Enantiomerically enriched (1R,2R)-2- bromoindan-1-ol (-)-1 and its (1S,2S)-acetate (+)-2 were obtained by this method.
- Igarashi, Yoshio,Otsutomo, Shinya,Harada, Masayuki,Nakano, Shigeru,Watanabe, Shoji
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- The absolute configuration of 2-bromo-2,3-dihydro-1H-inden-1-ols
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All four possible stereoisomers of cis- and trans-2-bromo-2,3-dihydro-1H-inden-1-ols, which are important intermediates in the synthesis of biologically active compounds, were synthesized and their configurations were studied by enzymatic kinetic resoluti
- Prysiazhnuk, Dmitry V.,Rusanov, Eduard B.,Kolodiazhnyi, Oleg I.
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p. 3023 - 3031
(2021/08/13)
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- A useful propionate cofactor enhancing activity for organic solvent-tolerant recombinant metal-free bromoperoxidase (perhydrolase) from Streptomyces aureofaciens
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The oxidative brominating activity of an organic solvent-tolerant recombinant metal-free bromoperoxidase BPO-A1 with C-terminal His-tag (rBPO-A1), from Streptomyces aureofaciens found to depend on various additives. These included carboxylic acids, used as cofactors and alcohols, used as water-miscible organic solvents. Enzyme activity was significantly enhanced by using propanoic acid (PA) as a cofactor, which had a high Log D at pH 5.0 and ethylene glycol with a low Log P. The positional specificity of oxidative hydroxybromination for olefins, using rBPO-A1 and PA in the presence of methanol, was higher compared to a non-enzymatic reaction using peracetic acid. The oxidative bromination step, occurring after enzymatic peroxidation step, is suggested to be pseudoenzymatic.
- China, Hideyasu,Ogino, Hiroyasu
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p. 327 - 332
(2019/07/12)
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- A convenient synthesis of (1S,2R)-1,2-indene oxide and trans-(1S,2S)-2-bromo-1-indanol via oxazaborolidine-catalyzed borane reduction
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A facile synthesis of (1S,2R)-indene oxide with >99% e.e. and (1S,2S)-trans-2-bromo-1-indanol with 87% e.e. has been established by employing CBS-oxazaborolidine-catalyzed asymmetric borane reduction of 2-p-toluenesulfonyloxy-1-indanone using N-ethyl-N-isopropylaniline-borane complex as the borane carrier.
- Choi, Ok Kyoung,Cho, Byung Tae
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p. 903 - 907
(2007/10/03)
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- Process for producing Trans-2 bromoindan-1-ol
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A cheap industrial method for making trans-2-bromoindan-1-ol. Trans-2-bromoindan-1-ol represented by Formula (II) is made by hydrolysing 1,2-dibromoindane represented by General Formula (I) (where the configuration of the bromine atoms on position 1 and position 2 can be trans or cis, or it can be a mixture of trans and cis isomers). Trans-2-bromoindan-1-ol represented by Formula (II) can also be made by brominating indene to synthesize 1,2-dibromoindane, and then continuously hydrolysing this 1,2-dibromoindane without isolating it. 1,2-Dibromoindane can also be made by reacting indene with hydrogen bromide in the presence of hydrogen peroxide.
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- Enzymatic resolution of indene bromohydrin acetate using immobilized lipase
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Enzymatic resolution of indene bromohydrin acetate by hydrolysis or alcoholysis in the presence of immobilized lipase from Candida antarctica (Novozym 435) has been investigated. Enantiomerically enriched (1S,2S)-(+)-2-bromoindan-1-ol and (1R,2R)-(-)-1-acetoxy-2-bromoindan were obtained when indene bromohydrin acetate was treated with Novozym 435 and cyclohexanol in dibutyl ether for 30 hours at 40°C.
- Igarashi, Yoshio,Otsutomo, Shinya,Harada, Masayuki,Nakano, Shigeru
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p. 2833 - 2837
(2007/10/03)
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- Enantioselective Ester Hydrolyses Employing Rhizopus nigricans. A Method of Preparing and Assigning the Absolute Stereochemistry of Cyclic Alcohols
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The mold Rhizopus nigricans has been used to hydrolyze enantioselectively the acetates of several series of benzocycloalken-3-ols and 2-substituted cycloalkanols to yield chiral alcohols.The configurations of the alcohols formed were established.The absolute stereochemistries of 25 of the 26 alcohols obtained were found to conform to a generalization based on the effective sizes of substituents on the carbinol carbon.The relative sizes of substituents required for agreement were identical with those employed in Horeu's method of establishing the absolute stereochemistry of the same compounds.The use of these microbially mediated hydrolyses to assign the absolute stereochemistry of cyclic secondary alcohols is compared to Horeau's method and to the use of empirical relations between the absolute stereochemistry of an enantiomer and the order, relative to its antipode, in which it is eluted from a chiral (Pirkle) column.
- Kasai, Masaji,Kawai, Ken-ichi,Imuta, Mitsuru,Ziffer, Herman
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p. 675 - 679
(2007/10/02)
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- Chemical Synthesis and Optical Purity Determination of Optically Active 1,2-Epoxyindan and Alcohol Products which are also derived from Mammalian or Microbial Metabolism of Indene or Indanones
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(+)-trans-2-Bromo-1-hydroxyindan (5) has been resolved into its enantiomers by preparative h.p.l.c. or fractional crystallization of the bromo-menthyloxy-acetoxydiastereoisomers (6a) and (6b).The bromohydrin (5) or bromo-esters (6a, 6b and 7) have in turn been converted into (-)-(1R,2S)-1,2-epoxyindan (2), (-)-(1R,2R)-trans-1-acetoxy-2-bromoindan (7), (+)-(1S)-indanol (8), (-)-(1R,2R)-trans-indan-1,2-diol (3), and (-)-(1S,2R)-cis-indan-1,2-diol (4).The optical purity of the alcohol products (3), (4), and (8) was determined by n.m.r. and h.p.l.c. analysis of their 2-methoxy-2-phenyl-2-trifluoromethylacetates.The previously unknown optical purity of the chiral alcohols (3), (4), (5), and (8), which had been isolated in earlier mammalian and microbial metabolism studies, has also been deduced.
- Boyd, Derek,Sharma, Narain D.,Smith, Alistair E.
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p. 2767 - 2770
(2007/10/02)
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- MICROBIALLY MEDIATED ENANTIOSELECTIVE HYDROLYSIS OF RACEMIC ACETATES
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The enantioselective hydrolyses of a series of racemic hydroaromatic acetates by Rhizopus nigricans to produce optically active alcohols are described.A rule predicting the absolute stereochemistry of the resulting alcohols is proposed.
- Kawai, Ken-ichi,Imuta, Mitsuru,Ziffer, Herman
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p. 2527 - 2530
(2007/10/02)
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