The alkaloids : a review of the literature published between .... 5.1975

Excerpt. © Reprinted by permission. All rights reserved. The Alkaloids Volume 5A Review of the Literature Published Between July 1973 and June 1974By J. E. SaxtonThe Royal Society of ChemistryCopyright © 1975 The Chemical SocietyAll rights reserved.ISBN: 978-0-85186-297-2ContentsChapter 1 Biosynthesis By R. B. Herbert, 1, Chapter 2 Pyrrolidine, Piperidine, and Pyridine Alkaloids By V. A. Snieckus, 56, Chapter 3 Tropane Alkaloids By J. E. Saxton, 69, Chapter 4 The Pyrrolizidine Alkaloids By J. E. Saxton, 77, Chapter 5 Indolizidine Alkaloids By J. E. Saxton, 87, Chapter 6 The Quinolizidine Alkaloids By J. E. Saxton, 93, Chapter 7 Quinoline, Quinazoline, Acridone, and Related Alkaloids By V. A. Snieckus, 103, Chapter 8 β-Phenethylamines and the Isoquinoline Alkaloids By H. O. Bernhard and V. A. Snieckus, 111, Chapter 9 Amaryllidaceae and Related Alkaloids By V. A. Snieckus, 170, Chapter 10 Erythrina and Related Alkaloids By V. A. Snieckus, 176, Chapter 11 Indole Alkaloids By J. A. Joule, 183, Chapter 12 Lycopodium Alkaloids By V. A. Snieckus, 228, Chapter 13 The Diterpenoid Alkaloids: Chemistry and Synthesis By S. W. Pelletier and S. W. Page, 230, Chapter 14 Steroidal Alkaloids of the Apocynaceae, Buxaceae, Asclepiadaceae, and of the Salamandra–Phyllobates Group By F. Khuong-Huu and R. Goutarel, 242, Chapter 15 Solanum and Veratrum Steroidal Alkaloids By R. B. Herbert, 256, Chapter 16 Miscellaneous Alkaloids By V. A. Snieckus, 265, Author Index, 291, CHAPTER 1BiosynthesisBY R. B. HERBERT'Being very anxious to find by experiment some support for this still purely speculative view....''It was completely unforeseen and opens to physiology new horizons, distant, but sure'L. Pasteur1 IntroductionAs this is the fifth of these Reports the Reporter is prompted to look back over the past five years in an attempt to recall the important developments of the period. There has of course been a prodigious amount of experimental work and it can be said fairly accurately that the gross topography of the biosynthesis of almost all the plant bases is now known. In a general sense, and rising out of consideration of the detail of biosynthetic pathways, it is the tracing of the stereochemistry of the biological processes which has proved the most fascinating and stimulating both from an intellectual and from an experimental point of view. As a worthwhile consequence more effort is being expended in attempts to understand the enzymic processes involved in biosynthetic processes. In a different direction a recent development has been the harnessing of plants for the synthesis of unnatural alkaloids. At its most sophisticated this can also provide information on enzyme function.The major siege that was laid against the redoubtable problem of the biosynthesis of a large group of indole alkaloids, represented by ajmalicine (1), akuammicine (2), and catharanthine (3), had been raised by the beginning of the quinquennium with the discovery that the non-indolic C9-C10 unit of each (indicated by heavy bonding) had a common terpenoid origin and that loganin (4) is a key intermediate. More information followed, and related pathways to the Cinchona and Ipecac alkaloids were delineated. Yet there remains fascinating detail to be uncovered.The solution to the enigma of the biosynthesis of colchicine (5) is of longer standing. More details on the unexpected but simple pathway to this non-basic alkaloid have come with the publication of full papers.In the light of established pathways to aporphine alkaloids (see p. 15) study of the biosynthesis of glaucine (6) and related bases in Dicentra eximia might have been expected to yield orthodox results. On the contrary, however, a novel pathway was unearthed which implicates dienone intermediates of quite unexpected structure: (7)/(8) for glaucine (6). There is good evidence that the dienone (7) is also involved in the elaboration of the Erythrina alkaloids, along a pathway which has several remarkable features.Hidd