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Enzymatic Resolution, Desymmetrization and Dynamic Kinetic Asym-metric Transformation of 1,3-Cycloalkanediols
Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
Ansvarig organisation
2006 (Engelska)Ingår i: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 71, nr 17, s. 6309-6316Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

An efficient desymmetrization of cis-1,3-cyclohexanediol to (1S,3R)-3-(acetoxy)-1-cyclohexanol ((R,S)-2a) was performed via Candida antarctica lipase B (CALB)-catalyzed transesterification, in high yield (up to 93%) and excellent enantioselectivity (ee's up to >99.5%). (R,R)-Diacetate ((R,R)-3a) was obtained in a DYKAT process at room temperature from (1S,3R)-3-acetoxy-1-cyclohexanol ((R,S)-2a), in a high trans/cis ratio (91:9) and in excellent enantioselectivity of >99%. Metal- and enzyme-catalyzed dynamic transformation of cis/trans-1,3-cyclohexanediol using PS-C gave a high diastereoselectivity for cis-diacetate (cis/trans = 97:3). The (1R,3S)-3-acetoxy-1-cyclohexanol (ent-(R,S)-2a) was obtained from cis-diacetate by CALB-catalyzed hydrolysis in an excellent yield (97%) and selectivity (>99% ee). By deuterium labeling it was shown that intramolecular acyl migration does not occur in the transformation of cis-monoacetate to the cis-diacetate.

Ort, förlag, år, upplaga, sidor
American Chemical Society , 2006. Vol. 71, nr 17, s. 6309-6316
Nationell ämneskategori
Organisk kemi
Identifikatorer
URN: urn:nbn:se:su:diva-25248DOI: 10.1021/jo060002nOAI: oai:DiVA.org:su-25248DiVA, id: diva2:199232
Anmärkning
Part of urn:nbn:se:su:diva-789Tillgänglig från: 2006-01-04 Skapad: 2006-01-04 Senast uppdaterad: 2017-12-13Bibliografiskt granskad
Ingår i avhandling
1. Deracemization of Functionalized Alcohols via Combined Ruthenium and Enzyme Catalysis
Öppna denna publikation i ny flik eller fönster >>Deracemization of Functionalized Alcohols via Combined Ruthenium and Enzyme Catalysis
2006 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

The major part of this thesis describes the synthesis of enantiopure alcohols and diols by combining ruthenium-catalyzed racemization or epimerization and lipase-catalyzed asymmetric transformations. A minor part of this thesis is focused on ruthenium-catalyzed redox reactions for transfer hydrogenation of 1,3-cycloalkanediketones.

Kinetic resolution of racemic γ-hydroxy acid derivatives was performed via Pseudomonas cepacia lipase (PS-C)-catalyzed transesterification. γ-Hydroxy esters and γ-hydroxy amides were studied showing in higher selec-tivity and yields for the γ-hydroxy amides. The enzyme PS-C tolerates both variation in the chain length and different functionalities giving good to high enantioselectivity. Combining enzymatic kinetic resolution with a ruthenium-catalyzed racemization led to a dynamic kinetic resolution (DKR). The use of 2,4-dimethyl-3-pentanol as a hydrogen source to suppress ketone formation in the dynamic kinetic resolution increased the yields of the acetate product. The synthetic utility of this procedure was illustrated by the practical synthesis of the γ-lactone (R)-5-methyltetrahydrofuran-2-one.

A distereoselective transformation of cis/trans-1,3-cyclohexandiol using Candida antarctica lipase B (CALB)-catalyzed transesterification was of interest. Desymmetrization of cis-1,3-cyclohexanediol to the (R-monoacetate was successfully accomplished. Enantiopure (R,R)-diacetate was obtained from the (R)-monoacetate in a DYKAT process at room tem-perature. Metal- and enzyme-catalyzed transformation of cis/trans-1,3-cyclohexanediol using PS-C, gives a high diastereoselectivity for cis-diacetate. The (S)-mono-acetate was obtained from cis-diacetate by CALB-catalyzed hydrolysis. In addition, it was shown, by the use of deuterium-labeling that intramolecular acyl migration does not occur in the transformation of cis-monoacetate to the cis-diacetate.

Ruthenium-catalyzed transfer hydrogenation of 1,3-cyclohexanedione under microwave heating was developed as an efficient and fast method for the preparation of 1,3-cycloalkandiols.

Ort, förlag, år, upplaga, sidor
Stockholm: Institutionen för organisk kemi, 2006. s. 51
Nationell ämneskategori
Organisk kemi
Identifikatorer
urn:nbn:se:su:diva-789 (URN)91-7155-200-6 (ISBN)
Disputation
2006-01-26, Magnélisalen, Kemiska övningslaboratoriet, Svante Arrhenius väg 12 A, Stockholm, 13:00
Opponent
Handledare
Tillgänglig från: 2006-01-04 Skapad: 2006-01-04 Senast uppdaterad: 2012-06-26Bibliografiskt granskad

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