G. N. Dorofeenko

Quantum chemistry of carbohydrates : Part I. The electronic structure of some pentoses

Abstract The simple LCAO-MO method of inductive parameters, in the form derived by Del Re, has been applied to the calculation of the electronic structure of some pentoses. The calculated data have been used for the interpretation of some chemical properties of pentoses.

Synthesis of 1-C-substituted, unsaturated ketoses

Abstract Using the Wittig reaction, higher α,β-unsaturated ketose derivatives, having substituents at C-1, were synthesised from the acetylated aldehydo forms of D -galactose, D -glucose, and D -mannose, using (acetyl- and aroyl-methylene) triphenylphosphoranes. The structures of the ketose derivatives were examined by i.r. and u.v. spectroscopy. In the deacetylated products, the presence of acyclic ketose structures was indicated by periodate oxidation studies. Certain properties of the ketose derivatives are influenced by the nature of the substituent at C-1. The Wittig reaction enables olefinic bonds to be introduced into monosaccharides which may then be converted into 2,3-dideoxy derivatives.

Synthesis of β-carbolinyl sugars

Abstract Decomposition of penta- O -acetyl-l-deoxy-l-diazo- keto - D - gluco -heptulose, in the presence of N -methylindole and copper powder as catalyst, results in the formation of penta- O -acetyl-l-deoxy-l-( N -methylindol-3-yl)- keto - D - gluco -heptulose ( 1 ). Compound 1 is acylated by carboxylic anhydrides at C-2 of the N -methylindole moiety, and cyclisation of the intermediate diketone, in the presence of 70% perchloric acid, gives indolo-[2,3- c ]-pyrylium perchlorates. With aqueous ammonia, these perchlorates are easily transformed into β-carbolinyl sugars that are close structural analogues of the indole alkaloids harmane, harmine, and melinonine.

Synthesis of pyrylium salts and pyridine bases by the bisacylation of cyclic tertiary alcohols

The catalytic acylation of 1-methyl- and 1-ethylcyclopentan-1-ols, 1-methyl- and 1-ethylcyclohexan-1-ols, 1-methylcycloheptan-1-ol, and 1-methyl- and 1-ethyl-1-tetralols with carboxylic acid anhydrides in the presence of 70% HClO4 has been studied. A method for the synthesis of substituted 3,4-cycloalkeno-3′,4′-dihydro(3,4∶2′, 1′)naphthopyrylium salts and the corresponding pyridine bases has been developed.

Reaction of pyrylium salts with heterocyclic amines

It has been established that in the reaction of 2, 4, 6-trimethylpyrylium perchlorate with 2-, 3-, and 4-aminopyridines, cytosine, adenine, guanine, and the corresponding nucleosides, and also with 2-amino-1-methylbenzimidazole, 2-amino-4-methylthiazole, 2-amino-4-phenylthiazole, 2-amino-6-bromobenzo-thiazole, and 2-amino-6-methoxybenzothiazole, either the corresponding quaternary pyridinium salt is formed or the pyrylium ring opens, depending on the basicity of the amino group.

Synthesis of cycloalkenopyrylium salts

Acylation of cyclopentylidenecyclopentanone, cyclohexenylcyclohexanone, and cycloneptenylcycloheptanone with anhydrides of aliphatic acids in the presence of 70% perchloric acid is studied. A simple method of synthesis of 2-alkyl-3, 4; 5, 6-bicycloalkenopyrylium salts is given. Treatment of the pyrylium salts with ammonia gives 2-alkyl-3, 4; 5, 6-bicyclopenteno- and cycloheptenopyridine in good yields.

Synthesis of 2-alkyl-6-phenyl-3, 4-c cycloheptenopyrylium salts

A method is given for synthesizing 2-alkyl-6-phenyl-3, 4-cycloheptenopyrylium perchlorates, obtained in 45–55% yields by acylating cycloheptenylacetophenone with anhydrides of aliphatic acids in the presence of 70% perchloric acid. Treatment of the pyrylium salts with ammonia gives a good yield of 2-alkyl-6-phenyl -3, 4-cycloheptenopyridine.