147918-39-6Relevant articles and documents
Synthese der Theonelladine A, B, C, D und von Niphatesin A
Teubner, Achim,Gerlach, Hans
, p. 161 - 166 (2007/10/02)
The pyridine alkaloids theonelladine A-D (1-4) and niphatesine (5) of marine origin have been synthesized starting either from 3-(4,4-dibromo-3-butenyl)pyridine (6) or from 3-pyridinecarbaldehyde.Reaction of 6 with two equivalents of BuLi gave the lithiated derivative of the alkyne 7, which could be alkylated with 1-bromo-10-(tetrahydro-2-pyranyloxy)decane (8) to yield the alkynol 9 after methanolysis.Selective hydrogenation of 9 with Lindlar palladium catalyst gave (Z)-14-(3-pyridyl)-11-tetradecen-1-ol (11). - Addition of the Grignard reagent of 12-(benzyloxy)-1-bromododecane (13) to 3-pyridinecarbaldehyde gave 17, which was first oxidized (Swern) to give 18 and then reduced (Wolff-Kishner) to give 14.Hydrogenolysis of the benzyl ether 14 yielded 15.The alcohol group in 9, 11, and 15 was converted into the tosyloxy group by reaction with tosyl chloride/pyridine.Subsequent reactions of the tosylates 10, 12, and 16 either with an excess of methylamine/ethanol or of ammonia/ethanol gave the pyridine alkaloids 1-5 in high yields as p-toluenesulfonates. Key Words: Pyridines/Alkaloids/Theonelladines A-D/Niphatesine A/4-(3-Pyridyl)-1-butin.