Bicyclic 5-6 Systems: Purines
نویسنده
چکیده
7.11.5.1 Thermal and Photochemical Reactions 405 7.11.5.2 Reactions with Electrophiles 406 7.11.5.2.1 N-Alkylation 406 7.11.5.2.2 C-Allcylation and arylation 408 7.11.5.2.3 Reaction with diazonium ions 409 7.11.5.2.4 Oxidation of ring atoms 409 7.11.5.2.5 Halogenation 410 7.11.5.2.6 Metal complexes 410 7.11.5.3 Reactions with Nucleophiles 411 7.11.5.3.1 Reduction 411 7.11.5.3.2 Amination and hydrolysis 412 7.11.5.4 Reactions with Free Radicals 412
منابع مشابه
Photochemical synthesis of nucleoside analogues from cyclobutanones: bicyclic and isonucleosides.
The preparation of two nucleoside analogues are reported. Both syntheses involve a key photochemical ring-expansion of cyclobutanones to an oxacarbene and its subsequent scavenging by 6-chloropurine. The synthesis of a bicyclic (locked) purine starts from a oxabicycloheptanone with a hydroxymethyl pendant. The preparation of an isonucleoside uses a cyclobutanone with an alpha-substituted 6-chlo...
متن کاملA T\i’ew Synthesis of the Purines Adenine, Hypo- Xanthuse, Xanthine, and Isoguanine
The studies of Emil Fischer (1) on the chemical nature of the bases, adenine and guanine, derived from nucleic acids and of the alkaloids such as caffeine, theobromine, and theophylline obtained from plants showed them to possess a common bicyclic ring structure (I), consisting of a pyrimidine ring fused with an imidazole ring. The first total syntheses from simpler molecules were carried out b...
متن کاملOn the harmonic index of bicyclic graphs
The harmonic index of a graph $G$, denoted by $H(G)$, is defined asthe sum of weights $2/[d(u)+d(v)]$ over all edges $uv$ of $G$, where$d(u)$ denotes the degree of a vertex $u$. Hu and Zhou [Y. Hu and X. Zhou, WSEAS Trans. Math. {bf 12} (2013) 716--726] proved that for any bicyclic graph $G$ of order $ngeq 4$, $H(G)le frac{n}{2}-frac{1}{15}$ and characterize all extremal bicyclic graphs.In this...
متن کاملSynthesis and structural characterization of pincer type bicyclic diacyloxy- and diazaselenuranes.
Synthesis and structural characterization of a new class of pincer type bicyclic diacyloxy- and diazaselenuranes is reported. The reaction of dimethyl 2-bromo-5-tert-butylisophthalate (28) with sodium benzeneselenolate affords the corresponding monoselenide, dimethyl 5-tert-butyl-2-(phenylselanyl)isophthalate (29). Reduction of 29 with LiAlH(4) provides 5-tert-butyl-2-(phenylselanyl)-1,3-phenyl...
متن کاملSynthesis and Biological activity of new 5-Methyl-3-Oxo-N2 [5’- Carbonyl-(4’-Aryl-6’methyl)-1’,2’,3’,4’–Tetrahydropyrimidine-2’- One]Pyrazolidines
INTRODUCTION In recent years, synthesis of combination towards various heterocyclic rings has been interest for the source of lead molecules possesses wide range of pharmacological activities. Most of the compounds having pyrimidine and pyrazolidinone nucleus exhibits pharmacological action. [1-3].A broad spectrum of biological activities like antiinflammatory [4], antibacterial [5], antifungal...
متن کامل