- RAPAMYCIN ANALOGS AND USES THEREOF
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The present invention provides compounds, compositions thereof, and methods of using the same.
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Paragraph 00379-00380
(2020/01/08)
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- Regioselective monochloro substitution in carbohydrates and non-sugar alcohols via Mitsunobu reaction: Applications in the synthesis of reboxetine
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A regioselective high yielding monochloro substitution (chlorohydrin formation) via Mitsunobu reaction is reported. In carbohydrates and sterically hindered non-sugars, only the primary hydroxyl group is chlorinated, whereas in the non-sugar 1,2- and 1,3-alcohols, predominantly the secondary chloride substitution occurs. The versatile methodology provides indirect access to epoxides with the retention of configuration, as against conventional Mitsunobu reaction which generates epoxides with inversion. The methodology was successfully used as a key step in the synthesis of optically active diastereoisomers of the antidepressant drug reboxetine from (R)-2,3-O- cyclohexylidene-d-glyceraldehyde in ~43% overall yields. The Royal Society of Chemistry.
- Dar, Abdul Rouf,Aga, Mushtaq A.,Kumar, Brijesh,Yousuf, Syed Khalid,Taneja, Subhash Chandra
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supporting information
p. 6195 - 6207
(2013/09/12)
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- METHOD OF PREPARATION OF OPTICALLY ACTIVE ALCOHOLS
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The present invention relates to a method for preparing chiral alcohol having optical activity. More specifically, the present invention relates to a method for preparing (S)-chiral alcohol with a high yield and a high optical purity by mixing achiral substrates such as racemic alcohol or ketone with metal catalyst and protein hydrolase to perform a dynamic kinetic resolution reaction.
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Page/Page column 16
(2010/02/10)
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- Organic co-solvents restore the inherently high enantiomeric ratio of lipase B from Candida antarctica in hydrolytic resolution by relieving the enantiospecific inhibition of product alcohol
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The enantiomeric ratio in the hydrolysis of racemic 3-chloro-1- phenylmethoxy-2-propyl butanoate with lipase B from Candida antarctica, CALB, is raised from E=50 to E=180 upon addition of acetone to the aqueous medium. This co-solvent effect is now explained as an enantiospecific inhibition of the lipase by the liberated alcohol. In the range from 0 to 30% acetone, the effect correlates with the increased solubility of the alcohol in the reaction medium. Free and immobilized CALB show similar behaviour.
- Lundhaug, Kamilla,Overbeeke, P.L. Antoine,Jongejan, Jaap A.,Anthonsen, Thorleif
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p. 2851 - 2856
(2007/10/03)
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- Enzymatic resolution of butanoic esters of 1-phenylmethyl and 1-[2-phenylethyl]ethers of 3-chloro-1,2-propanediol
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The enzymatic hydrolysis of butanoic esters of 1-phenylmethyl- and 1-[2-phenylethyl] ethers of 3-chloro-1,2-propanediol has been studied by using lipases. Highest enantiomeric ratio was obtained with PPL for the phenylmethyl ether and with Amano SAM II for the phenylethyl ether. The absolute configurations of the products was verified in two ways. Both the produced alcohols and the remaining esters were converted into the corresponding glycidyl ethers which also were synthesised in homochiral forms starting from (S)-epichlorohydrin. The produced alcohols and the remaining esters were prepared independently from (S)-epichlorohydrin.
- Partali,Waagen,Alvik,Anthonsen
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p. 961 - 968
(2007/10/02)
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- Enzymes in Organic Synthesis: Synthesis of Highly Enantiomerically Pure 1,2-Epoxy Aldehydes, Epoxy Alcohols, Thiirane, Aziridine, and Glyceraldehyde 3-Phosphate
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This paper describes a chemoenzymatic procedure for the synthesis of (R)- and (S)-glycidaldehyde diethyl acetal (4 and 5). 2-Acetoxy-3-chloropropanal diethyl acetal (1c) was enantioselectively hydrolyzed by LP-80 lipase to give (S)-3-chloro-2-hydroxypropanal diethyl acetal (2c) and the unreacted acetate (3c), both in >95percent calculated yield and >98percent ee.Both products were subsequently converted to epoxides 4 and 5, respectively.Resolutions of 2-acetoxy-1-(benzyloxy)-3-chloropropane (11a) and 3-(allyloxy)-2-acetoxypropyl p-toluenesulfonate (14b) were similarly carried out to give the corresponding optically active 2-hydroxy and 2-acetoxy derivatives in 90percent and >95percent ee.These products were subsequently converted to the corresponding 1,2-epoxides.Nucleophilic opening of epoxide 4 was exemplified by the syntheses of (R)-3-azido-2-hydroxypropanal and D-glyceraldehyde 3-phosphate.Conversion of the chiral epoxides to thiirane and aziridine was also described.
- Pederson, Richard L.,Liu, Kevin K.-C.,Rutan, James F.,Chen, Lihren,Wong, Chi-Huey
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p. 4897 - 4901
(2007/10/02)
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