Show simple item record

dc.contributor.authorKarodia, Nazira*
dc.contributor.authorAitken, R.A.*
dc.contributor.authorMassil, T.*
dc.contributor.authorYoung, R.J.*
dc.date.accessioned2009-08-17T10:31:47Z
dc.date.available2009-08-17T10:31:47Z
dc.date.issued2002
dc.identifier.citationR.A. Aitken, R.A., Karodia, N., Massil, T. and Young, R.J. (2002). Flash vacuum pyrolysis of stabilised phosphorus ylides: Part 17. Preparation of aliphatic amino acid derived y-alkoxycarbonyl-amino-B-oxo ylides and pyrolysis to give a,B-acetylenic y-amino acid and GABA analogues. Journal of the Chemical Society, Perkin Transactions 1: Organic and Biomolecular Chemistry. Vol. 2002, No. 4, pp. 533-541.en
dc.identifier.urihttp://hdl.handle.net/10454/3312
dc.descriptionNoen
dc.description.abstractA series of eleven alpha-aminoacyl stabilised phosphorus ylides 9-19 have been prepared by condensation of N-alkoxycarbonyl protected amino acids with Ph3P=CHCO2Et using a carbodiimide peptide coupling reagent. Upon ash vacuum pyrolysis at 600 degreesC, these undergo extrusion of Ph3PO to give the corresponding, alpha,beta-acetylenic gamma-amino esters 21-29, 33 and 34 in moderate yield. In two cases the terminal alkynes 30 and 31 are also formed. The beta-aminoacyl ylide 20 from beta-alanine similarly gives the alpha,beta-acetylenic delta-amino ester 35 upon pyrolysis. Regioselective addition of HBr to the triple bond of one acetylenic ester 25 was observed giving a mixture of E and Z alpha-bromoacrylates 36. Hydrogenation of the N-Cbz acetylenic esters 21-23 and 33 results in N-deprotection and hydrogenation of the triple bond to afford the chiral GABA analogues 37-40 in 70 --> 95% ee as determined by F-19 NMR of their Mosher amides. Fully assigned C-13 NMR spectra of all the ylides and acetylenic ester derivatives are presented.en
dc.language.isoenen
dc.subjectStereospecific synthesisen
dc.subjectDerivativesen
dc.subjectMechanismen
dc.subjectFacileen
dc.titleFlash vacuum pyrolysis of stabilised phosphorus ylides. Part 17. Preparation of aliphatic amino acid derived gamma-alkoxycarbonyl-amino-beta-oxo ylides and pyrolysis to give alpha,beta-acetylenic gamma-amino acid and GABA analoguesen
dc.status.refereedYesen
dc.typeArticleen
dc.type.versionNo full-text available in the repositoryen
dc.identifier.doihttps://doi.org/10.1039/b110243e


This item appears in the following Collection(s)

Show simple item record