Record Details

Studies towards the synthesis of few biologically active chiral(Gama)-butyrolactone based molecules employing 2-hydroxycitric acid lactones

Shodhganga@INFLIBNET

View Archive Info
 
 
Field Value
 
Title Studies towards the synthesis of few biologically active chiral(Gama)-butyrolactone based molecules employing 2-hydroxycitric acid lactones
 
Contributor Saud, I Ibnu
 
Description (2S, 3s) and (2S,3R)-tetrahydro-3-hydroxy-5-oxo-2,3-furandicarboxylic acids
(Garcinia and Hibiscus acids) have been isolated form plant sources in large amounts. Several attempts were made for the reduction of carboxyiate functional groups, often selectively, using various borane reagents namely BH3THF, BH3SMe2. BH3/trimethyl borate,NaBH4/12 etc. Selective reduction of ester group geminal to hydroxyl group in methyl (2S, 3s)- tetrahydro-3-hydroxy- 5-0x0-2,3-furandicarboxylate, using borane dimehtyl sulphide and catalytic amount of sodium borohydride resulted in (25 3R)-terahydro-3-hydroxy-3-(hydroxymethyl)- 5-0x0-2-furancarboxylate. a versatile ch~ron. Subsequently the diol obtained was converted to analogue of (+)- avenaciolide ((3aR. 6aS)-3a-hydroxytetrahydrofuro [3, 4-blfuran-2.6-dione], a biologically significant bislactone skeleton using ptoluene sulphonic acid. Attempts were made to convert (2S, 3R)-terahydro-3-hydroxy-3- (hydroxymethy1)-5-0x0-2-furancarboxylate to analogues of CIS-whisky and cognac lactones. Interestingly much selectivity was not observed in the case of (2S, 3R)- tetrahydro-3-hydroxy-5-0x0-2, 3-furandicarboxylic acid when reduced using borane dimehtylsulphide and catalytic amount of sodium borohydride. The observed difference in reactivity of the said reagent towards methyl (2S, 3s) and (2S, 3R)-
etrahydro-3-hydroxy-5-0x0-2.3-furandicaoate have been analysed mechanistically. Starting with Garcinia acid functionalized chiral butenolides, structural motifs useful for the synthesis of a variety of biologically interesting molecules bearing 2(5H) furanone subunits, have been prepared. The trialkyl (IS, 25) and (IS, 2R)- 1. 2-dihydroxy-I, 2, 3-propanetricarboxylates obtained from the title acids have been effectively employed as chiral ligands in Sharpless asymmetric epoxidation and sulphoxidation reactions.
Bibliography p.192-201, list of patents, publications and conference proceedings and abstract included
 
Date 2010-08-06T06:40:44Z
2010-08-06T06:40:44Z
2010-08-06
January 2006
 
Type Ph.D.
 
Identifier http://hdl.handle.net/10603/518
 
Language English
 
Rights university
 
Format v, 201p.
CD
 
Publisher Kottayam
Mahatma Gandhi University
School Of Chemical Science
 
Source INFLIBNET