5 research outputs found
Donor-Acceptor Cyclopropane Ring Opening with 6-Amino-1,3-dimethyluracil and Its Use in Pyrimido[4,5- b]azepines Synthesis
A scandium trifluoromethanesulfonate-catalyzed reaction of donor-acceptor cyclopropanes with 6-amino-1,3-dimethyluracil was found to proceed as three-membered ring opening via nucleophilic attack of the C(5) atom of an ambident nucleophile serving as an enamine equivalent. It was shown that, under basic conditions, the obtained products underwent cyclization to 6,7-dihydro-1H-pyrimido[4,5-b]azepine-2,4,8-triones, an interesting subclass of nucleobase analogues. © 2021 American Chemical Society
Expanding Stereoelectronic Limits of endo- tet Cyclizations: Synthesis of Benz[ b]azepines from Donor-Acceptor Cyclopropanes
The importance of intramolecular constraints in cyclic transition-state geometries is especially pronounced in n-endo-tet cyclizations, where the usual backside approach of a nucleophile to the breaking bond is impossible for the rings containing less than eight atoms. Herein, we expand the limits of endo-tet cyclizations and show that donor-acceptor cyclopropanes can provide a seven-membered ring via a genuine 6-endo-tet process. Substrates containing a N-alkyl-N-arylcarbamoyl moiety as an acceptor group undergo Lewis acid-induced cyclization to form tetrahydrobenz[b]azepin-2-ones in high yields. The reaction proceeds with the inversion of the configuration at the electrophilic carbon. In this process, a formally six-membered transition state yields a seven-membered ring as the pre-existing cycle is merged into the forming ring. The stereochemistry of the products can be controlled by the reaction time and by the nature of Lewis acid, opening access to both diastereomers by tuning of the reaction conditions. © 2021 American Chemical Society
Hypolipidemic effect and leskol tolerance in hypertensive patients with hypercholesterolemia: Results of multicenter trial
Hypertensive patients with hyperlipidemia are at high risk to develop coronary heart disease (CHD). Chemotherapeutic correction of hyperlipidemia seems most reliable modality to prevent CHD. Hypolipidemic effect and tolerance of leskol (fluvastatin) in dietotherapy-resistant hypercholesterolemia were studied in 74 patients with essential hypertension treated with hypotensive drugs. The patients were included in a multicenter trial. A 12-week course reduced total cholesterol level under 6.2 mmol/l in 59% of the patients, under 5.2 mmol/l in 29% of them. LDLP cholesterol lowered to 3.5% in 34% of the patients. Mean apo B diminished by 23%. There was a 27% decrease in the proportion of atherogenic fraction apo B to antiatherogenic fraction of transport proteins apo A-I. Leskol is well tolerated and effective against hypercholesterolemia, it is safe in relation to side effects and blood biochemistry
Hypolipidemic effect and leskol tolerance in hypertensive patients with hypercholesterolemia: Results of multicenter trial
Hypertensive patients with hyperlipidemia are at high risk to develop coronary heart disease (CHD). Chemotherapeutic correction of hyperlipidemia seems most reliable modality to prevent CHD. Hypolipidemic effect and tolerance of leskol (fluvastatin) in dietotherapy-resistant hypercholesterolemia were studied in 74 patients with essential hypertension treated with hypotensive drugs. The patients were included in a multicenter trial. A 12-week course reduced total cholesterol level under 6.2 mmol/l in 59% of the patients, under 5.2 mmol/l in 29% of them. LDLP cholesterol lowered to 3.5% in 34% of the patients. Mean apo B diminished by 23%. There was a 27% decrease in the proportion of atherogenic fraction apo B to antiatherogenic fraction of transport proteins apo A-I. Leskol is well tolerated and effective against hypercholesterolemia, it is safe in relation to side effects and blood biochemistry