The study is dedicated to the investigation of the chemical transformations of allobetulone, betulone aldehyde in the aldol-crotonic condensation, reduction, epoxidation, Corey-Chaykovsky, reductive amination, Grignard, Wittig and other reactions. The possible areas of practical application of synthesized compounds are suggested.
The modification of the propenone fragment of 2-heterylidene derivatives of allobetulone and alobetulin, as well as of the model compounds of 2-ylidene derivatives of cholestanone and 16-ylidedehydroepiandrosterones, has led to the new high-performance chiral supplements for the liquid crystal compositions with selective reflection of light in the visible region of the spectrum. These compositions may be suitable for creating of the materials for low-energy devices displaying information on their basis. The connection between the features of their molecular structure and the induction of spiral supramolecular order in mesophases was determined by the X-ray diffraction studies and calculation methods.
By studying the transformations of betulone aldehyde under the conditions of reducing amination, it was stated that under the treatment by H2-Pd/C the C=N bond and isopropenylene fragment are reduced, but the carbonyl group in the 3rd position of the lupane core remains unchanged. Conversely, the conversion of azomethines to aminoalcohols in the NaBH4-MeOH medium is accomplished with the remaining of the isopropenyl group. A new series of α,b-unsaturated ketones was synthesized for the first time from the betulonic aldehyde by the Wittig reaction. In the reaction with phenylmagnesium bromide the mentioned aldehyde forms a mixture of (R:S) 28-phenyl-28-hydroxylup-20(29)-en-3-one in 1:5 ratio; the main S-isomer turns into 28-phenylallobetulone in the acidic medium.
A number of novel 1,2,3-triazole derivatives of alobetulin and dehydro-epiandrosterone obtained by the click-reaction method forms gels in cyclohexanol, toluene, ethanol, methanol and methanol-dichloromethane mixtures. It was established that the dehydroepiandrosterone-based gel in cyclohexanol medium could be used to extract organic dyes from aqueous solutions.
The hybrid compounds with the potential antineoplastic activity based on betulonic acid with 1,2,3-triazole and methotrexate are synthesized. In contradicttion to methotrexate, these compounds revealed a tropic effect on the 1,2-dipalmitoylphosphatidylcholine in an artificial membrane. However, in the penetrating ability experiment on Caco-2 cells, these conjugates were inferior to methotrexate and showed activity at the reference level of atenolol.
