StatusThe thesis was presented on the 23 October, 2012
Approved by NCAA on the 15 November, 2012
Abstract– 0.77 Mb / in romanian
Key words: stereoselective synthesis, terpenoids, norlabdanic compounds, drimane sesquiterpenoids, biologically active compounds, ozonization, photooxidative dehydrogenation, halogenation, nitrogen and halogen containing terpenic compounds.
The purpose and objectives of the thesis. The dissertation is devoted to the elaboration of chemo-, regio- and stereoselective methods of the synthesis of optically active norlabdanic and drimanic compounds, including nitrogen and halogen containing derivatives, on the basis of accessible natural labdane diterpenoids- sclareol and abienols; the elucidation of reaction mechanisms and optimal conditions of obtaining the mentioned compounds, as well as the target-orientated synthesis of new compounds with high potential of biological activity, odorant and aromatizing properties, with further possibilities for industrial application.
Novelty and scientific originality. New fundamental knowledge has been obtained in establishing the influence of structural, steric and electronic factors in terpenic compounds on the processes of chemo-, regio- and stereoselective formation of C-C and C-N bonds. The selectivity of photolytic and ozonolytic degradation reactions of labdane and drimanic compounds has been studied for the purpose of obtaining polyfunctional terpenoids derivatives, precursors of bioactive compounds. The studies have been carried out with the elucidation of the chemo-, structural and steric regularities of: photooxidative dehydrogenation reaction of Δ8- drimen- and Δ8-11-homodrimen-7-ones into α,α1-dienones and regioselective dehydration of tertiary methylcyclohexane alcohols with the Swern reagent.
Fundamentally new results obtained for science and practice have identified a new line of investigations in the chemistry of terpenoids, by the elaboration of the original chemo-, regio- and stereoselective methods of the synthesis of a large number of new optically active norlabdanic and drimanic compounds, including nitrogen and halogen containing compounds, on the basis of available labdane diterpenoids. These compounds are chiral synthones that are important for obtaining higher terpenoids and compounds of practical value, including biologically active substances, which are of great interest for application in such industries, as pharmaceutical, perfumery, cosmetic, and as aromatizing agents in tobacco industry.
The practical values of the work. Preparation of 12-hydroperoxy-8α,12-epoxy-11- bishomodrimane started with 11- bishomodrimane-8α-ol-12-one and was accomplished in quantitative yield. It is a novel compound with pronounced antimycotic properties, which can be used for treatment of fungus diseases. New aroma compositions were worked out for the tobacco industry, they giving the aroma and dominant note of cumarine to tobacco. Results of research concerning the composition of aroma with the content of sclareoloxide as an important ingredient were patented and implemented at Chisinau tobacco factory in the production of «МТ» and «Tutun-CTC» cigarettes.