81555-85-3Relevant academic research and scientific papers
One-pot deracemization of sec-alcohols: Enantioconvergent enzymatic hydrolysis of alkyl sulfates using stereocomplementary sulfatases
Schober, Markus,Toesch, Michael,Knaus, Tanja,Strohmeier, Gernot A.,Van Loo, Bert,Fuchs, Michael,Hollfelder, Florian,Macheroux, Peter,Faber, Kurt
, p. 3277 - 3279 (2013/04/23)
Hand in hand: The title transformation was achieved using a pair of sulfatases acting through inversion and retention of configuration on opposite substrate enantiomers. Using Pseudomonas aeruginosa arylsulfatase PAS with alkylsulfatase PISA1 in one-pot l
The substrate spectrum of the inverting sec-alkylsulfatase Pisa1
Schober, Markus,Knaus, Tanja,Toesch, Michael,MacHeroux, Peter,Wagner, Ulrike,Faber, Kurt
, p. 1737 - 1742 (2012/07/31)
The substrate spectrum of the inverting alkylsulfatase Pisa1 was investigated using a range of sec-alkyl sulfate esters bearing aromatic, olefinic and acetylenic moieties. Perfect enantioselectivities were obtained for substrates bearing groups of different size adjacent to the sulfate ester moiety. Insufficient selectivities could be doubled by using dimethyl sulfoxide (DMSO) as co-solvent. Hydrolytically unstable benzylic sulfate esters could be sufficiently stabilised by introduction of electron-withdrawing substituents. Overall, Pisa1 appears to be a very useful inverting alkylsulfatase for the deracemisation of rac-sec-alcohols via enzymatic hydrolysis of their corresponding sulfate esters, which furnishes homochiral products possessing the 'anti-Kazlauskas' configuration. Copyright
Chromium(II) Reagents; 1. Reduction of α-Acetylenic Ketones to trans-Enones
Smith, Amos B.,Levenberg, Patricia A.,Suits, Joan Z.
, p. 184 - 189 (2007/10/02)
The preparation and chromium(II)-induced reduction of twelve α-acetylenic ketones are reported.In general only trans-olefinic products were observed; the yields ranged from 40-84percent.A particular advantage of this protocol is its selectivity, thereby permitting use with a wide variety of functionalities.
ASYMMETRIC REDUCTIONS OF PROPARGYL KETONESAN EFFECTIVE APPROACH TO THE SYNTHESIS OF OPTICALLY-ACTIVE COMPOUNDS
Midland, M. Mark,Tramontano, Alfonso,Kazubski, Aleksander,Graham, Richard S.,Tsai, David J. S.,Cardin, Daniel B.
, p. 1371 - 1380 (2007/10/02)
Propargyl ketones are readily reduced by the asymmetric reducing agent B-3-pinanyl-9-borabicyclo-nonane (Alpine-borane).The reagent prepared from (+)-α-pinene and 9-BBN provides the R enantiomer while the S enantiomer can be obtained from (-)-α-pinene.Alternatively the S enantiomer ca be prepared from the reagent derived from 9-BBn and the benzyl ether of nopol (6,6-dimethyl-bicyclohept-2-ene-2-ethanol).The limiting factor in obtaining high enantiomeric induction is often the enantiomeric purity of the α-pinene.With 100percent enantiomerically pure α-pinene, propargyl alcohols of essentially 100percent ee can be obtained.A predictive rationalization of the transition state leading to this remarkable selection is presented.The acetylene unit of the propargyl alcohol provides a convenient handle for transformations to other useful, optically-active products.The use of propargyl alcohols for the synthesis of optically-active α- and β-substituted γ-lactones, and δ-lactones is illustrated.
Reduction of α,β-Acetylenic Ketones to (S)-Propargyl Alcohols of High Enantiomeric Purity
Midland, Mark M.,Kazubski, Aleksander
, p. 2814 - 2816 (2007/10/02)
(S)-Propargyl alcohols may be obtained in 86-96percent enantiomeric purity by asymmetric reduction of α,β-acetylenic ketones with the 9-borabicyclononane (9-BBN) adduct of nopol benzyl ether.
NB-Enantride, a New Chiral Trialkylborohydride for the Asymmetric Reduction of Ketones
Midland, M. Mark,Kazubski, Aleksander
, p. 2495 - 2496 (2007/10/02)
NB-Enantride, prepared by hydroboration of nopol benzyl ether with 9-borabicyclononane (9-BBN) followed by treatment with tert-butyllithium, is a new asymmetric reducing agent which is especially effective for aliphatic ketones such as 2-butanone.
