Synthesis of 2-aryl-4-(4-β-D-allopyranosyloxyphenyl)4,6,7,8-tetrahydroquinolin-5(1H)-one derivatives under solvent-free conditions and study of sedative activity
Under solvent-free conditions, syntheses of 2-aryl-4-(4-β-D-allopyranosyloxyphenyl)-4,6,7,8tetrahydroquinolin-5(1H)-one derivatives were carried out from chalcone (2a–2e), cyclohexane-1,3-dione (3), and NH4OAc in excellent yield without using any catalysts. The structure of the new compounds were characterized by 1H NMR, IR, and HR-MS spectroscopy. The preliminary bioassay tests of 4a–4j indicated that compounds 4b, 4e, and 4f exhibited potent sedative and hypnotic activity.
Further Daphniphyllum Alkaloids from the Bark of Daphniphyllum macropodum Miq.
Four new Daphniphyllum alkaloids, namely dehydroxymacropodumine A (1), 4,21-deacetyl-23-demethyl-deoxyyuzurimine (2), 7-oxo-deoxyyuzurimine (3), and 4-acetoxydaphmanidin B (4), together with seven known related alkaloids, were isolated from the bark of Daphniphyllum macropodum Miq. The structures of new compounds 1–4 including relative configurations were elucidated on the basis of detailed spectroscopic data analysis and by comparison with related known compounds. Dehydroxymacropodumine A (1) possesses a rare eleven-membered macrolactone ring representing the second example of this backbone isolated from natural sources.
Catalytic removal of tert-butyldimethylsilyl (TBS) ether by PVP-I
Abstract A mild, efficient and rapid protocol the deprotection of alcoholic TBDMS ethers using PVP-1 as catalyst in methanol, the procedure of deprotection of various TBDMS ethers were found to be very convenient, easy work-up, high yielding.