Oxopipecolic acid

The ring-opening/cyclization sequence (Section III,C) has also been extended to the synthesis of protected 5-oxopipecolic acid 61 (n = 2). Thus, when ylide 60 (n = 2) is treated with rhodium(II) trifluoroacetate, it affords 51% of 61 (n = 1) (93CC1434). 

Recently, analogous nitrones have been used by others in the synthesis of (2S)-4-oxopipecolic acid [45] and (-l-)-negamycin [46]. Chiacchio et al. [47] applied the Vasella-type nitrone 53 in an enantioselective synthesis of isoxazolidinyl thymine 55 (Scheme 10.18). As illustrated, the A-furanosyl nitrone 53 reacted with vinyl acetate to give a 1 1 mixture of two isoxazolidines 54 epimeric at C-5. In contrast to the poor cw/tran -diastereoselectivity, the diastereofacial selectivity... 

Machetti, F, Cordero, F M, De Sarlo, F, Guama, A, Brandi, A, A new s3mthesis of (2S)-4-oxopipecolic acid by thermal rearrangement of enantiopure spirocyclopropaneisoxazolidine. Tetrahedron Lett, 37, 4205-4208, 1996. 

D-penicillamine, streptolidine, 3-aminosalicylic acid D-a-pipecolic acid, 4-oxopipecolic acid, 2-(]-amino-2-rnethylpropyl) thiazole-4-carboxylic acid Thiostreptoic acid, thiostreptine... 

Mo-Phe, JV-methyl- d imethylaminopheny la-lanine, -methyl-j>-methyiaminophenylala-nine, 4-oxopipecolic acid, Sar... 

The hetero Diels-Alder reaction <01H1591, 01TL5693> and dipolar cycloadditions continue to constitute important approaches to piperidines. Kibayashi and co-workers used an intramolecular acylnitroso Diels-Alder reaction to synthesize (-)-lepadins A,B, and C from an acyclic precursor <01JOC3338>. An intramolecular nitrone cycloaddition was used by Machetti and co-workers to produce both enantiomers of 4-oxopipecolic acid <01T4995>. Their synthesis proceeds from a nitrone bearing an a-methylbenzylamine chiral auxiliary. Noteworthy in this report is the presence of large-scale experimental procedures the nitrone formation and cycloaddition reactions were performed on 285 mmol and 226 mmol scales, respectively. 

Fig. 6. Manosk representation of the X-ray structure of pristinamycin 1 to compare the accessibility of the methylene groups adjacent to the ketone of the oxopipecolic acid residue...

The biosynthesis of pristinamycin 1 by Streptomyces pristinaespiralis is currently being studied in the RHONE POULENC laboratories. The natural amino acids threonine and proline have been shown to be incorporated directly into pristinamycin 1 and radiolabeled " C-pristinamycin I a has been prepared by incorporation of [U- C]proline. Interesting studies on the biosynthesis of virginiamycin Si described by Kingston and co-workers [44] showed that the phenylglycine residue was derived from phenylalanine via an intermolecular transfer of nitrogen. More recently, they have demonstrated that both the (S)-4-oxopipecolic acid (8) and 3-hydroxypicolinic acid (9) residues are derived from lysine via the two possible pathways depicted in Scheme 2 in which the... 

The first analogues (11) and (12) of this antibiotic, in which the unusual 4-oxopipecolic acid was replaced by a more accessible proline or 4-hydroxy-proline nucleus, were obtained respectively by Ondetti in 1965 [52], and in 1967 by Jolles and Bouchaudon [53]. 

The potential interest of substituting the 4-oxopipecolic acid moiety by some other more polar residue (in order to solubilize the antibiotic) led Anteunis and co-workers to synthesize an analogue (14) of virginiamycin Si [59]. 

Treatment of pristinamycin with primary and secondary amines in the presence of the cyanoborohydrido-anion [66] afforded, in moderate yields, the semi-synthetic derivatives (20) via reductive amination of the carbonyl function of the 4-oxopipecolic acid residue. 

Oxindole alkaloids, K9-10 Oxindoles, A56 6-oxoleucotylin, T45 4-oxopipecolic acid, AlO... 

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