G. A. Panosyan

Synthesis of Nicotinic Acid Derivatives by the Reaction of Salts of 1-Alkyl-4,6-dimethyl-2-pyrimidinylacetic Acid Esters with Amines

A study was carried out on the enamine rearrangement of iodoalkylates of the ethyl ester of 4,6-dimethyl-2-pyrimidinylacetic acid to give ethyl esters of 2-alkylamino-4,6-dimethylnicotinic acid, which proceeds upon the action of various amines. The reaction with amines containing an alkyl substituent different from that at the quaternized nitrogen atom of the pyrimidinium salt leads to the formation of products of rearrangement and transamination. In the presence of water, the rearrangement is accompanied by the formation of the ethyl ester of 1,2-dihydro-2-oxo-4,6-dimethylnicotinic acid.

(2E)-4,4-Dimethoxy-2-butenal in the Synthesis of Conjugated Dienes and Dienals

Using (2E)-4,4-dimethoxy-2-butenal as starting compound, methods were developed for synthesis of (2E,4E)- and (2E,4Z)-dimethoxyalkadienes. Deacetalization of the latter gives with high yield the corresponding dienals which are naturally occurring compounds and also synthons for preparation of conjugated dienes as key compounds for building up other natural products.

Synthesis of (±)-cis-tetradec-5-en-4-olide — The racemate of the sex pheromone of the Japanese beetle

A three-stage method has been developed for the stereoselective synthesis of (±)-cis-tetradec-5-en-4-olide — the racemate of the sex pheromone of the Japanese beetlePopillia japonica C. The key reactions used were the stereoselective cis reduction of a triple bond with the aid of heterogeneous hydrogenation catalysts (zinc-copper couple, nickel boride, Lindlar catalyst) and the radical lactonization of conjugated systems by the action of acetic acid in the presence of manganese acetate.

Reaction of N-Acyl-γ-aminobutyric Acids with 3-Ethoxycarbonylbenzotriazole 1-Oxide

Reactions of α,β-dehydrodipeptides containing a terminal γ-aminobutyric acid residue with 3-ethoxycarbonylbenzotriazole 1-oxide at 90-100°C result mainly in cleavage of the peptide bond. In the cold, the corresponding ethyl ester and N-acyl-γ-butyrolactam are formed. Analogous reactions with N-benzoyl- and N-benzyloxycarbonyl-γ-aminobutyric acids leads to formation of the corresponding ethyl esters.