Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Pumiliotoxin absolute configuration

Fig. 6. Structures of pumiliotoxins. Absolute configurations are known for 251D, 307A, and 323A and are assumed to be the same for the others. All occur in dendrobatid frogs except for 3QSB, which has been delected only in ranid frogs (Mantella) (73), and eryihro-323A, which has been detected only in ranid (Mantella) and myobatrachid frogs (Pseu-dophryne) (73,85,86). Fig. 6. Structures of pumiliotoxins. Absolute configurations are known for 251D, 307A, and 323A and are assumed to be the same for the others. All occur in dendrobatid frogs except for 3QSB, which has been delected only in ranid frogs (Mantella) (73), and eryihro-323A, which has been detected only in ranid (Mantella) and myobatrachid frogs (Pseu-dophryne) (73,85,86).
Extracts from skins of the neotropical frog Dendrobates tricolor from Ecuador have given the alkaloid 8-hydroxy-6-(2-methylhexylidene)azabicyclo[4.3.0]non-ane (4), the structure and absolute configuration of which have been determined by X-ray crystallography of the hydrochloride salt. This alkaloid is the first structurally defined member of the pumiliotoxin A class of dendrobatid alkaloids. Spectroscopic studies (m.s. and n.m.r.) have allowed the formulation of the... [Pg.59]

Fig. 10. Pumiliotoxin C formula, structure, and absolute configuration determined by X-ray analysis (32,33). Fig. 10. Pumiliotoxin C formula, structure, and absolute configuration determined by X-ray analysis (32,33).
When aldehyde 103 is reacted with methylmagnesium bromide followed by a Swem oxidation of the resulting alcohol, the ketone 107 is obtained. Subsequent deketalization and treatment with acetic anhydride in pyridine affords (27 ,3 S)-108, which has been used to determine the absolute configuration of a portion of pumiliotoxin B [44]. [Pg.330]

Oppolzer, W. FrostI, W. Weber, H. P. "The Total Synthesis of d/-Pumiliotoxin-C" Helv. Chim. Acta 1975, 58, 593. Oppolzer, W. Flaskamp, E. "An Enantioselective Synthesis and the Absolute Configuration of Natural Pumiliotoxin-C" Helv. CNm. Acta 1977, 60, 204. Oppolzer, W. Flaskamp. E. Bieber. L. W. "Efficient Asymmetric Synthesis of Pumilbtoxin C via Intramolecluar [4+2] Cycloaddition" Helv. Chim. Acta 2001, 84,141-145. Eor a related approach to pumiliotoxin-C and other Dendrobatid alkaloids see Banner, E. J. Stevens, E. D. Trudell, M. L. Tetrahedron Lett. 2004,45,4411-4414. [Pg.357]

Fig. 17. Structure of gephyrotoxin 223AB. The absolute configuration is unknown, but is arbitrarily depicted so that the absolute configuration at C-5 corresponds to C-2 of pumiliotoxin C which also has a n-propyl substituent... Fig. 17. Structure of gephyrotoxin 223AB. The absolute configuration is unknown, but is arbitrarily depicted so that the absolute configuration at C-5 corresponds to C-2 of pumiliotoxin C which also has a n-propyl substituent...
Oppolzer, W., and E. Flaskamp An enantioselective synthesis and the absolute configuration of natural pumiliotoxin-C. Helv. Chim. Acta 60, 204—201 (1977). [Pg.336]

See other pages where Pumiliotoxin absolute configuration is mentioned: [Pg.65]    [Pg.68]    [Pg.178]    [Pg.178]    [Pg.178]    [Pg.178]    [Pg.428]    [Pg.428]    [Pg.302]    [Pg.305]   
See also in sourсe #XX -- [ Pg.12 , Pg.294 ]

See also in sourсe #XX -- [ Pg.12 , Pg.294 ]



SEARCH



Absolute configuration

© 2024 chempedia.info