EPC syntheses employing (2S, 3S) and (2S, 3R) – Tetrahydro-3-Hydroxy-5-Oxo-2,3-Furandicarboxylic acids: syntheses of analogues of Quararibea Metabolite Chiral Enolic-Lactones
Shodhganga@INFLIBNET
View Archive InfoField | Value | |
Title |
EPC syntheses employing (2S, 3S) and (2S, 3R) – Tetrahydro-3-Hydroxy-5-Oxo-2,3-Furandicarboxylic acids: syntheses of analogues of Quararibea Metabolite Chiral Enolic-Lactones
- |
|
Contributor |
Saud, I Ibnu
|
|
Subject |
Chemistry
|
|
Description |
(2S,3S)- and (2S,3R)-tetrahydro-3-hydroxy-5-oxo-2,3-furandicarboxylic acids (Garcinia and Hibiscus acids) have been isolated in large amounts from cheap natural sources and the optical purity of the molecules were asserted by VCD analysis. A systematic literature survey for biologically potent and#947;-butyrolactone based natural products has been conducted. The study revealed that there are several and#947; butyrolactone based molecules which have matching structure and stereochemistry with that of the title compounds. Attempts were made to synthesize analogues of the Quararibea metabolite chiral enolic-and#947;-lactone (3- hydroxy-4,5-(R)-dimethyl-2(5H)-furanone) from (2S,3S)- and (2S,3R)- tetrahydro-3-hydroxy-5-oxo-2,3-furandicarboxylic acids. Reaction of Dialkyl (2S,3S)- and (2S,3R)-tetrahydro-3-hydroxy-5-oxo-2,3-furandicarboxylates with POCl3 in pyridine followed by treatment with diazomethane resulted in the isolation of 2S-Dialkyl 4-methoxy-5-oxo-2,5-dihydro-2,3-furandicarboxylates, analogues of the Quararibea metabolite chiral enolic-and#947;-lactone (3-hydroxy-4,5- (R)-dimethyl-2(5H)-furanone). Certainly an unusual and#945;-hydroxylation of and#947;- butyrolactone (dialkyl tetrahydro-3-hydroxy-5-oxo-2,3-furandicarboxylates) is involving with POCl3. The feasibility of and#945;-hydroxylation with methanesulfonyl chloride failed instead resulted in the formation of aromatic dialkyl 5- [(methylsulfonyl)oxy]-2,3-furandicarboxylates. This clearly indicates the involvement of a (2,3)-sigmatropic rearrangement leading to and#945;-hydroxylation of dialkyl tetrahydro-3-hydroxy-5-oxo-2,3-furandicarboxylates. Trialkyl (1S,2S)- and (1S,2R)-1,2-dihydroxy-1,2,3-propane tricarboxylates was converted to (4S,5S)-4- (2-Hydroxy-2,2-diarylethyl)-2,2-Dimethyl-and#945;,and#945;,and#945; ,and#945; -tetraaryl-1,3-dioxalane-4,5- dimethanols. This TADDOL analogue was found to be effective chiral dopants for the phase transformation of nematic liquid crystal into cholesteric liquid crystal.
References p.220-234 |
|
Date |
2013-01-28T04:36:30Z
2013-01-28T04:36:30Z 2013-01-28 n.d. August 2006 n.d. |
|
Type |
Ph.D.
|
|
Identifier |
http://hdl.handle.net/10603/6771
|
|
Language |
English
|
|
Relation |
212
|
|
Rights |
university
|
|
Format |
234p.
- None |
|
Coverage |
Chemistry
|
|
Publisher |
Kottayam
Mahatma Gandhi University School Of Chemical Sciences |
|
Source |
INFLIBNET
|
|