Quinolizidine chemistry

Enantiospecific syntheses of amino derivatives of benzo[ ]quinolizidine and indolo[2,3- ]quinolizidine compounds have also been achieved via A-acyliminium ion cyclization reactions, as an alternative to the more traditional Bischler-Napieralski chemistry (see Section 12.01.9.2.2). One interesting example involves the use of L-pyroglutamic acid as a chiral starting material to construct intermediates 240 via reaction with arylethylamine derivatives. Diisobutylaluminium hydride (DIBAL-H) reduction of the amide function in 240 and subsequent cyclization and further reduction afforded piperidine derivatives 241, which stereoselectively cyclized to benzo[ ]quinolizidine 242 upon treatment with boron trifluoride (Scheme 47) <1999JOC9729>. 

Hartmann, T. 1988. Secondary metabolism of lupins Biosynthesis, translocation and accumulation of the quinolizidine alkaloids. In Proceedings of the 5th International Lupin Conference. (Twardowski, T., ed.) pp. 64-78. Poznari, Polish Academy of Sciences, Institute of Bioorganic Chemistry. 

Hirai, M. Y., Suzuki, H., Yamazaki, M. and Saito, K. 2000. Biochemical andpatrial molecular characterization of bitter and sweet form of Lupinus angustifolius, an experimental model for study of molecular regulation of quinolizidine alkaloids biosynthesis. Chemistry and Pharmacy. Bulletin, 48 1458-1461. 

Robins DJ (1995) Biosynthesis of pyrrolizidine and quinolizidine alkaloids. The Alkaloids, Chemistry and Pharmacology (ed Cordell GA) Vol 46. Academic, San Diego, pp 1-61. 

Pyrrolizidine alkaloids, chemistry and toxicology of 86MI9. Quaternary benzo[c]phenanthridine alkaloids 90CCC2840. Quinolizidine alkaloids 87WCH393. 

Robins, D.J. Biosynthesis of pyrrohzidine and quinolizidine alkaloids. In The Alkaloids Chemistry and Pharmacology Cordell, G.A., Ed. Academic Press San Diego, CA, 1995 46, 1-61. 

Aromatic quinolizidines, advances in chemistry of 82AHC(31)1. 8-Azasteroids, total synthesis of 84UK1014. 

Phthalides are valuable synthons for obtaining several biologically active compounds and natural products. Naphthols, anthraquinones and anthraquinone antibiotics, isoquinolones, phthalide isoquinolines, indolizidine and quinolizidine alkaloids, and berbine alkaloids have been synthesised with phthalides as the starting compounds. Some of the syntheses, which have interesting chemistry, are described below. The required phthalides, in some cases, have been synthesised through aromatic lithiation reactions, while in others by more conventional methods. 

Hie first, by Lounastnaa and Hanhinen, updates an area of indole alkaloids which has been neglected in the series for over 30 years, namely, the ajmaline group of alkaloids, where numerous advances in chemistry and biosynthesis have been made recently. The second chapter by Michael reports on the progress made in a vast area of alkaloid chemistry, those alkaloids with either an indolizidine or a quinolizidine nucleus derived from plant, marine animal, and fungal sources. 

There has been considerable development during the year in the chemistry of lythraceae alkaloids containing quinolizidine ring systems, especially in synthesis. 

Indole and isoquinoline alkaloids continue to play a dominant role. The apor-phinoids, comprising proaporphines, aporphines and related dimers, are treated separately, partly in order to reduce the burden on contributors aristolactams and aristolochic acids, which have not been reviewed since 1961, also are discussed in this chapter. This year the quinolizidine alkaloids, including the sesquiterpenoid Nuphar bases and the appropriate Lythraceae alkaloids, as well as azaphenalenes of plant and insect origin are reviewed together. Amaryllidaceae, Erythrina, imidazole, purine and peptide alkaloids are omitted from this volume, but it is expected that the chemistry of these groups covering the period 1974—1976 will be surveyed in Volume 7. 

The chapter related to this one in the first edition of Comprehensive Heterocyclic Chemistry (CHEC-I) <84CHEC-I(2)525> dealt mainly with quinolizinium ion, and quinolizine or quinolizidine were mentioned only as reaction products of the aromatic species. Since that time, new developments in the chemistry of quinolizinium compounds have been relatively scarce, and a number of reviews covering them, together with the earlier work, have appeared <81H(16)803,82AHC(3l)l, 91HOU(E7a)759, 92HOU(E7b)239, 92AHC(55)261>. For these reasons, this chapter is devoted mainly to nonaromatic compounds. 

Quinolizidine alcohols and amines react as nucleophiles in the expected way, yielding amides and esters. They can also take part in Mitsunobu-type chemistry, and thus conversion of equatorial hydroxyquinolizidines (157) to axial azides (158) has been accomplished by treatment with triphenyl phosphine, diethyl azodicarboxylates, and diphenyl phosphoryl azide (Equation (16)) <77TL1977>. 

Fig. 30.8 (a b). Labeling studies for quinolizidine alkaloid biosynthesis (modified from Herbert, 1988 and Spenser, 1985 used with permission of the copyright owners. The Royal Society of Chemistry, Cambridge and the International Union of Pure and Applied Chemistry, Oxford, respectively). 

Wink, M. and T. Hartmann, Enzymology of quinolizidine alkaloid biosynthesis, in Natural Products Chemistry 1984 (14th lUPAC Symposium on the Chemistry of Natural Products) (R, I. Zalewski and J. J. Skolik, eds.), Elsevier, Amsterdam, 1984. 

Advances in the chemistry of three groups of alkaloids are reviewed in this volume. The Sceletium and Phenanthroindolizidine-Phenanthro-quinolizidine groups were previously reviewed in Volume IX of this series and a chapter on the Solatium alkaloids appeared in Volume X. The present reports deal with the considerable research activity in these areas over the intervening years. 

Rizvi SJH, Mishra GP, Rizvi V (1989a) Allelopathic effects of nicotine on maize. 1. Its possible importance in crop rotation. Plant and Soil 116 289-291 Rizvi SJH, Mishra GP, Rizvi V (1989b) Allelopathic effects of nicotine on maize. Some aspects of its mechanism of action. Plant Soil 116 292-293 Robins DJ (1995) Biosynthesis of pyrroUzidine and quinolizidine alkaloids. In The alkaloids -chemistry and pharmacology, vol 46. Academic Press, San Diego, CA, USA, pp 1-62 Robins RJ, Walton NJ (1993) The biosynthesis of tropane alkaloids. In Cordell GA (ed) The alkaloids - chemistry and pharmacology, vol 44. Academic Press, San Diego (CA), USA, pp 115-187... 

Several other general reviews dealing with aspects of indoHzidine and quinolizidine alkaloid chemistry were pubHshed during the period under consideration. The series of annual reports in the Royal Society of Chemistry s journal Natural Product Reports, which provided regular coverage of both simple and various more complex indolizidine and quinolizidine alkaloids, ended in 2008.Another important review that dealt principally with pertinent alkaloids from ants and amphibians, slaframine, polyhydroxy-lated indolizidine alkaloids, and the lupin quinolizidine alkaloids was published in the series Studies in Natural Product Chemistry in 2002, and covered the period 1994 to 1999. ... 

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