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Pyridocarbazole alkaloids

A further extension of this strategy has been employed as a route to carbazoles, as illustrated by the synthesis of the system 116 from the 2-nitrobiphenyl derivative 117 (Equation 30) <20040L533>. A substituted 2-nitrobiphenyl derivative has been cyclized to a carbazole using P(OEt)3 en route to the pyridocarbazole alkaloid ellipticine <2006HCA111>. It should also be mentioned that annulation of o-(alkynyl)nitrobenzene precursors with TBAF or pyridine gave access to indol-3-one-l-oxides (isatogens) <2003T2497>. [Pg.283]

Kozikowski and Hasan (77JOC2039) used an intermolecular Diels-Alder reaction for the synthesis of the pyridocarbazole alkaloid ellipticine (456) (Scheme 57). Reaction of oxazolediene 454 with excess acetic acid at 145°C gave the pyridine 455 in 16% yield. Addition of methyllithium to cyanopy-ridine 455 followed by hydrolysis and cyclization with acetic acid afforded ellipticine (456). [Pg.308]

Carbon-carbon bond formation by intramolecular cyclization of conjugated iminium ions is also possible, as illustrated by the transformation of amine oxide (36) to (37), a key intermediate in the synthesis of the pyridocarbazole alkaloid ellipticine (38 Scheme 7). ... [Pg.916]

Joule and co-workers ° have described the synthesis of the pyridocarbazole (192) and derivatives containing a partially-reduced ring d, which are potential intermediates in the synthesis of the rare alkaloid subincanine, whose structure has not yet been unambiguously defined. [Pg.241]

It has been reported that the furoindole (361) underwent Diels-Alder reactions with DMAD, N-phenylmaleimide and benzyne to give the expected products <84JOC45l8>. Treatment of 3-chloro-4-iodo-pyridine with t-butyllithium followed by addition of (361) led to a mixture of the isomeric Diels-Alder adducts (362) and (363) in 15% yield. Deoxygenation and desulfonylation of (362) and (363), gave a readily separable mixture of the pyridocarbazole alkaloids ellipticine (364), and isoellipticine (365), respectively (Scheme 14) <84JOC45l8,83TL5435>. [Pg.998]

Details of the synthesis of ellipticine and related pyridocarbazole alkaloids by Gilbert et al. have now been published. "... [Pg.175]

Pyridocarbazole alkaloids, 21 Pyridon, 109, 127 Pyridone, 142, 143 Pyridon quinolizidine alkaloids, 141 Pyridostigmine, 158 Pyridoxal phosphate, 116 Pyriferines A-C, 65-67 Pyrolidines, 8... [Pg.458]


See other pages where Pyridocarbazole alkaloids is mentioned: [Pg.318]    [Pg.174]    [Pg.134]    [Pg.30]    [Pg.99]    [Pg.1215]    [Pg.146]    [Pg.321]    [Pg.331]    [Pg.209]    [Pg.209]    [Pg.474]    [Pg.6]    [Pg.551]    [Pg.240]    [Pg.243]    [Pg.551]    [Pg.22]    [Pg.119]    [Pg.37]    [Pg.151]    [Pg.21]    [Pg.9]    [Pg.437]    [Pg.453]   


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