Diterpenoid alkaloids chemistry

Total Synthesis of Chasmanine.—Wiesner and his co-workers38,39 have accomplished a landmark in diterpenoid alkaloid chemistry in their completion of the total synthesis of racemic chasmanine (49), a hexacyclic base with six oxygen functionalities. The synthesis of the intermediate (50) was reviewed in the previous Report (Vol. 7, pp. 257—259). 

Chapter 13 Recent Developments in Diterpenoid Alkaloid Chemistry... 

The earlier work on the chemistry of Ci9-diterpenoid alkaloids has been reviewed in Volumes IV (1), VII (2), and XII (3) of this series, in books on alkaloids by Boit (4) and Pelletier (5), in The Alkaloids, Specialist Periodical Reports, (6-8), and in other reviews (9, 10). This chapter deals with the recent developments in Ci9-diterpenoid alkaloid chemistry reported in the literature available to us since July 1968, as well as certain unpublished work from our laboratory. 

Only a moderate amount of work in diterpenoid alkaloid chemistry has been reported during the past year. A detailed report on the structure and chemistry of heteratisine has been published. The most active area has been that of the syntheses of these complex bases by Professor Karel Wiesner s group at the University of New Brunswick. Among their notable achievements have been the total syntheses of napelline and talatisamine. 

Studies on the diterpenoid alkaloids published during the past twelve months have provided much new structural and synthetic information on these complex plant bases. Twenty diterpenoid bases that are new or previously undetected in plant material have been reported from Aconitum and Delphinium species, and from Consolida ambigua and Garrya ovata. An extensive review of diterpenoid alkaloid chemistry has been published. ... 

Applications of N.M.R. Spectrometry to the C19 Diterpenoid Alkaloids 14-Acetylbrowniine.—A review of recent applications of carbon-13 n.m.r. spectrometry to the solution of some of the complex problems of C19 diterpenoid alkaloid chemistry has appeared. Using proton-decoupling techniques and additivity relationships, the carbon-13 chemical shifts for eighteen aconitine and lycoctonine-type alkaloids were assigned. Applications of these methods for the identification and structure elucidation of several new diterpenoid alkaloids were discussed. The new data presented in this work included the identification of... 

Peng, C. S., Chen, D. L., Chen Q. H. and Wang, F. P. 2005. New diterpenoid alkaloids from roots of Aconitum sinomontanum. Chinese Journal of Organic Chemistry, 25 1235-1239. 

Diterpenoid alkaloids have been isolated from the genera of the families Ranunculaceae (Aconitum, Consolida, Delphinium, Thalictrum), Garryaceae (Garraya), Rosaceae (Spiraea), and Compositae (Inula). These alkaloids can be divided into two broad categories norditerpenoid alkaloids (based on a C -skeleton) and the diterpenoid alkaloids (based on a Cft-skeleton).1 The chemistry of the diterpenoid alkaloids has been reviewed in earlier literature. ... 

BS Joshi and SW Pelletier, Recent Developments in the Chemistry of Norditerpenoid and Diterpenoid Alkaloids in Alkaloids Chemical and Biological Perspectives , (SW Pelletier, ed.), Vol 13, Chapter 4, pp. 292-2362, Pergamon Press, Amsterdam, 1999. 

Amiya T and Bando H (1988) Aconitum alkaloids. The Alkaloids, Chemistry and Pharmacology (ed Brossi A) Vol 34. Academic, San Diego, pp 95-179. Atta-ur-Rahman and Choudhary MI (1998) Chemistry and biology of steroidal alkaloids. The Alkaloids, Chemistry and Pharmacology (ed Cordell GA) Vol 50. Academic, San Diego, pp 61-108. Atta-ur-Rahman and Choudhary MI (1999) Diterpenoid and steroidal alkaloids. Nat Prod Rep 16, 619-635. Earlier reviews 1997, 14, 191-203 1995, 12, 361-379. 

Joshi BS and Pelletier SW (1999) Recent developments in the chemistry of norditerpenoid and diterpenoid alkaloids. Alkaloids, Chemical and Biological Perspectives (ed Pelletier SW) Vol 13. Elsevier, Amsterdam, pp 289-370. 

Wang FP and Liang XT (1992) Chemistry of the diterpenoid alkaloids. The Alkaloids, Chemistry and Pharmacology (ed Cordell GA) Vol 42. Academic, San Diego, 151-247. 

The chemistry of the diterpenoid alkaloids, rather than their structure elucidation by physical methods, has attracted more interest during the year covered by this Report. While several new alkaloids have been reported, most of the research on these polycyclic, polyfunctional bases has involved chemical conversions and synthetic methods. Most notably, Wiesner s group at New Brunswick, Canada, has reported a fourth-generation synthesis of the delphinine-type alkaloids. That this marvel of synthetic engineering accomplishes the stated goals1 of a highly efficient, fully regio- and stereo-specific synthesis of these complex natural products is abundantly clear. 

Surveys of recent developments in the chemistry of C2o diterpenoid alkaloids,4 of the alkaloids of Consolida ambigua,5 and of the synthesis of diterpenoid alkaloids by thermolysis6 have appeared. 

The diterpenoid alkaloids, isolated mainly from Aconitum and Delphinium species (Ranunculaceae), have been of great interest since the early 1800s because of their pharmacological properties. Extracts of Aconitum species were used in ancient times for treatment of gout, hypertension, neuralgia, rheumatism, and even toothache. Extracts have also been used as arrow poisons. Some Delphinium species are extremely toxic and constitute a serious threat to livestock in the western United States and Canada. Delphinium extracts also manifest insecticidal properties. In the last 30 to 40 years, interest in the diterpenoid alkaloids has increased because of the complex structures and interesting chemistry involved. 

The earlier work on the chemistry of C20-diterpenoid alkaloids has been reviewed in Volumes IV(4), VII(5), and Xll(6) of this treatise, in books on... 

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