Big Chemical Encyclopedia

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

Articles Figures Tables About

Quinolizinium ring synthesis

The remaining reactions for the establishment of a bond adjacent to the pyridine nitrogen of a potential quinolizinium ring are presumed to involve the attack of the unshared pair of electrons of the nitrogen upon a carbon bearing a halogen atom. The most direct synthesis of this type might involve the cyclization of l-(2-pyridyl)-4-halobutadiene (130)... [Pg.553]

All known alkyl and aryl quinolizinium salts have been produced by ring synthesis there are no reports of direct alkylation of an already formed quinolizinium salt. Alkyl and aryl groups (2-furyl is the only reported ex-... [Pg.56]

The only mononitroquinolizinium salts are the 10-nitrobenzo[c]- and the 10-nitrobenzo[b]quinolizinium derivatives.119,120 In the bicyclic series nitrohydroxyquinolizinium salts have been made by direct nitration,130 and nitro-4-quinolizones by nitration of 4-quinolizones, or by ring synthesis.34 All these nitrations are dealt with in Section IV,C. Nitro groups have been reduced catalytically, for example, to give amines 216130 and 217.120... [Pg.58]

Indole-2-carboxylic acids, 121, 252, 254 Indole-3-carboxylic acids, 253, 254 Indolenines, 84, 167, 169 dichloromethyl-, 68 quatemization of, 39 quinolines from, 69-71 ring expansion of, 69-71 Indolizmes, formylation of, 73 Indolo[l,2-a]pyrazinone, 119 Indolo[2,3-a]quinolizinium salts, synthesis of, 178... [Pg.214]

Benzo[a]quinoIizinium bromide, 7-methyl-electrochemical reductions, 2, 534 Benzo[c]quinolizinium bromide ring opening, 2, 533 Benzo[c]quinolizinium chloride hydrogenation, 2, 536 Benzo[c]quinoIizinium chloride, 6-amino-synthesis, 2, 554... [Pg.552]

Quinolizidines.—The quinolizidine nucleus is widespread in Nature and occurs in the lupin and other alkaloids. Earlier syntheses of these alkaloids suffered from poor stereospecificity of reactions, particularly in the reduction of quinolizinium salts to the reduced ring system. This problem has now been overcome and a total synthesis of ( )-deoxynupharidine achieved (Scheme 70). The reduction results in products with the correct configurations at C-4, C-7, and C-10, but the opposite... [Pg.298]


See other pages where Quinolizinium ring synthesis is mentioned: [Pg.330]    [Pg.294]    [Pg.351]    [Pg.57]    [Pg.59]    [Pg.312]    [Pg.87]    [Pg.551]    [Pg.571]    [Pg.905]    [Pg.551]    [Pg.571]    [Pg.289]    [Pg.19]    [Pg.184]    [Pg.1044]    [Pg.1055]    [Pg.184]   
See also in sourсe #XX -- [ Pg.498 ]

See also in sourсe #XX -- [ Pg.442 ]




SEARCH



Quinolizinium ring

© 2024 chempedia.info