Enantioselective Synthesis of 12-epi-PGF2α and 12,15-diepi-PGF2α
摘要:
An enantioselective synthesis of 12-epi-PGF(2 alpha), (3) and 12,15-diepi-PGF(2 alpha) (4), PG-like compounds that are probably generated in vivo by nonenzymatic, free-radical-induced peroxidation of arachidonic acid, has been achieved starting from the commercially available Corey lactone (9). The key strategy involves SmI2 reduction of the gamma,delta-epoxy-alpha,beta-unsaturated ester 7, followed by in situ trapping with hexanal; subsequent hydrogenation and decarboxylation affords the stereoselective construction of the lower side chain. This new method is expected to provide a convenient access to various PG-like isoprostanes derived from oxidation of arachidonic acid and cis-4,7,10,13,16,19-docosahexaenoic acid.
Stereodivergent Synthesis of All 15-F2 Isoprostanes
摘要:
Isoprostanes, lipid metabolites generated from free radical oxidation of membrane-bound arachidonic acid, have been detected in organisms subjected to oxidative stress; however, the function and cellular targets of the isoprostanes are unclear. As an initial step toward studying the biological role of these molecules, we report the preparation of all known and anticipated 15-F2 isoprostanes. The stereodivergent strategy to the complete isoprostane library features a ring-opening metathesis to introduce the cis-alkyl side chains that are characteristic of this class of molecules. Resolution to the individual stereoisomers can be accomplished by either a catalytic asymmetric reduction or an auxiliary-based separation protocol. In either case, the individual isomers can be converted to the corresponding 15-F2 isoprostanes through a straightforward functionalization of the carboxylic acid-containing side chain. The availability of this complete 15-F2 isoprostane library, containing both known and anticipated lipid metabolites, allows for the first time the side-by-side evaluation of these compounds in a variety of biological assays.
作者:Seong-Woo Hwang、Mustafa Adiyaman、Subhash P. Khanapure、Joshua Rokach
DOI:10.1016/0040-4039(95)02390-9
日期:1996.2
A novel synthesis of 12-epi-PGF2α5 is described. The key synthon 11, which has been used as a starting point for the synthesis, is produced by a radical cyclization process using thionocarbonate 9a. The radical cyclization of 9a to 11 has been studied in some detail.
Facile Preparation of (±)-12-Epiprostaglandins from 7-Oxabicyclo[2.2.1]hept-5-en-2-one<i>via</i>an all-<i>cis</i>-formyllactone related to<i>Corey</i>lactone
作者:Jean-Paul Vionnet、Philippe Renaud
DOI:10.1002/hlca.19940770710
日期:1994.11.2
The bicyclic monoselenoacetal 7, easily obtained from (±)-7-oxabicyclo[2.2.1]hept-5-en-2-one (6) via a radical addition-acyl migration sequence, was converted to racemic 12-epiprostaglandins 3 and 4. The key intermediate was the all-cis-formyllactone 2b related to Corey lactone (see 12; Scheme 1). The presence of a (tert-butyl)-dimethylsilyl protective group for the 11-OH substituent (prostaglandin
Enantioselective Synthesis of 12-<i>epi</i>-PGF<sub>2</sub><sub>α</sub> and 12,15-<i>diepi</i>-PGF<sub>2</sub><sub>α</sub>
作者:Sheng Lai、Dongreyoul Lee、Jong Sun U、Jin Kun Cha
DOI:10.1021/jo990906r
日期:1999.9.1
An enantioselective synthesis of 12-epi-PGF(2 alpha), (3) and 12,15-diepi-PGF(2 alpha) (4), PG-like compounds that are probably generated in vivo by nonenzymatic, free-radical-induced peroxidation of arachidonic acid, has been achieved starting from the commercially available Corey lactone (9). The key strategy involves SmI2 reduction of the gamma,delta-epoxy-alpha,beta-unsaturated ester 7, followed by in situ trapping with hexanal; subsequent hydrogenation and decarboxylation affords the stereoselective construction of the lower side chain. This new method is expected to provide a convenient access to various PG-like isoprostanes derived from oxidation of arachidonic acid and cis-4,7,10,13,16,19-docosahexaenoic acid.
Organopalladium approaches to prostaglandins. 11. Synthesis of PGF2.alpha. and 12-epi PGF2.alpha. by the controlled, one step, palladium-promoted, intermolecular coupling of three different alkenes
作者:Richard C. Larock、Nam Ho Lee
DOI:10.1021/ja00020a083
日期:1991.9
CLARK, MIKE A.;CONWAY, THERESA M.;CROOKE, STANLEY T., J. LIQUID CHROMATOGR., 10,(1987) N 12, 2707-2719
作者:CLARK, MIKE A.、CONWAY, THERESA M.、CROOKE, STANLEY T.