Total synthesis of vinblastine, vincristine, related natural products, and key structural analogues
- PMID: 19292450
- PMCID: PMC2727944
- DOI: 10.1021/ja809842b
Total synthesis of vinblastine, vincristine, related natural products, and key structural analogues
Abstract
Full details of the development of a direct coupling of catharanthine with vindoline to provide vinblastine are described along with key mechanistic and labeling studies. Following an Fe(III)-promoted coupling reaction initiated by generation of a presumed catharanthine radical cation that undergoes a subsequent oxidative fragmentation and diastereoselective coupling with vindoline, addition of the resulting reaction mixture to an Fe(III)-NaBH(4)/air solution leads to oxidation of the C15'-C20' double bond and reduction of the intermediate iminium ion directly providing vinblastine (40-43%) and leurosidine (20-23%), its naturally occurring C20' alcohol isomer. The yield of coupled products, which exclusively possess the natural C16' stereochemistry, approaches or exceeds 80% and the combined yield of the isomeric C20' alcohols is >60%. Preliminary studies of Fe(III)-NaBH(4)/air oxidation reaction illustrate a generalizable trisubstituted olefin scope, identify alternatives to O(2) trap at the oxidized carbon, provide a unique entry into C20' functionalized vinblastines, and afford initial insights into the observed C20' diastereoselectivity. The first disclosure of the use of exo-catharanthine proceeding through Delta(19',20')-anhydrovinblastine in such coupling reactions is also detailed with identical stereochemical consequences. Incorporating either a catharanthine N-methyl group or a vindoline N-formyl group precludes Fe(III)-promoted coupling, whereas the removal of the potentially key C16 methoxy group of vindoline does not adversely impact the coupling efficiency. Extension of these studies provided a total synthesis of vincristine (2) via N-desmethylvinblastine (36, also a natural product), 16-desmethoxyvinblastine (44) and 4-desacetoxy-16-desmethoxyvinblastine (47) both of which we can now suggest are likely natural products produced by C. roseus, desacetylvinblastine (62) and 4-desacetoxyvinblastine (59), as well as a series of key analogues bearing systematic modifications in the vindoline subunit. Their biological evaluation provided additional insights into the key functionality within the vindoline subunit contributing to the activity and sets the foundation on which further, more deep-seated changes in the structures of 1 and 2 will be explored in future studies.
Figures
References
-
- Neuss N, Neuss MN. In: The Alkaloids. Brossi A, Suffness M, editors. Vol. 37. Academic; San Diego: 1990. p. 229.
-
-
Noble RL, Beer CT, Cutts JH. Ann N Y Acad Sci. 1958;76:882.Noble RL. Lloydia. 1964;27:280.Svoboda GH, Nuess N, Gorman M. J Am Pharm Assoc Sci Ed. 1959;48:659. For related, naturally occurring bisindole alkaloids: see Leurosidine: Svoboda GH.Lloydia 196124173 Deoxyvinblastine: De Bruyn A, Sleechecker J, De Jonghe JP, Hannart J.Bull Soc Chim Belg 198392485Neuss N, Gorman M, Cone NJ, Huckstep LL. Tetrahedron Lett. 1968:783. N-Desmethylvinblastine: Simonds R, De Bruyn A, De Taeye L, Verzele M, De Pauw C.Planta Med 198450274. Desacetoxyvinblastine: Neuss N, Barnes AJ, Jr, Huckstep LL.Experientia 19753118. Desacetylvinblastine: Svoboda GH, Barnes AJ., JrJ Pharm Sci 1964531227.
-
-
- Owellen RI, Hartke CA, Dickerson RM, Haines FO. Cancer Res. 1976;36:1499. - PubMed
- Pearce HL. In: The Alkaloids. Brossi A, Suffness M, editors. Vol. 37. Academic; San Diego: 1990. p. 145.
- Borman LS, Kuehne ME. In: The Alkaloids. Brossi A, Suffness M, editors. Vol. 37. Academic; San Diego: 1990. p. 133.
- Fahy J. Curr Pharm Design. 2001;7:1181. - PubMed
-
- Moncrief JW, Lipscomb WN. J Am Chem Soc. 1965;87:4963. - PubMed
-
- Barnett CJ, Cullinan GJ, Gerzon K, Hoying BC, Jones WE, Newlon WM, Poore GA, Robison RL, Sweeney MJ, Todd GC, Dyke RW, Nelson RL. J Med Chem. 1978;21:88. - PubMed
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Other Literature Sources
