A versatile and effectual, three-component one pot (2π + 2π) cycloaddition reaction to the synthesis of substituted azetidines in excellent yields is described. The isonicotinic acid hydrazide (1) as starting materials. Design preparation N-(7-R)-2-oxa-8-azabicyclo[4.2.0]octan-8-yl)isonicotinamide derivatives (4a-h) was carried out by condensation isoniazid with aromatic aldehyde (2a-h), ZnCr2O...

In the title compound, C(23)H(24)N(2)O(7), the central 4H-pyran ring adopts a flattened boat conformation, whereas both cyclo-hexenone rings adopt envelope conformations, the C atom bearing the dimethyl substituent being the flap atom in each case. The mean and maximum deviation of the pyran ring are 0.0379 (4) and 0.0605 (3) Å. The mean plane of the pyran ring and the dinitro-benzene ring make...

The title compound, C15H14Br2O4 [systematic name: rac-(9S,10R)-3,9-dibromo-10-methoxy-8,8-dimethyl-9,10-dihydropyrano[2,3-h]chromen-2(8H)-one], is a pyran-ocoumarin derivative formed by the bromination of seselin, which is a naturally occurring angular pyran-ocoumarin isolated from the Indian herb Trachyspermum stictocarpum. In the mol-ecule, the benzo-pyran ring system is essentially planar, w...

We synthesized two series of androstane derivatives as inhibitors of type 3 and type 5 17β-hydroxysteroid dehydrogenases (17β-HSDs). In the first series, four monospiro derivatives at position C17 were prepared from androsterone (ADT) or epi-ADT. After the protection of the alcohol at C3, the C17-ketone was alkylated with the lithium acetylide of tetrahydro-2-(but-3-ynyl)-2-H-pyran, the triple ...

Infections are one of the most important causes of death, disability and inappropriate conditions for millions of people around the world. Therefore, the development in prognosis, prevention and treatment of infectious diseases made a considerable progress in designing and synthesis of new antimicrobial drugs. Nowadays, due to the increase in microbial resistance, discovery of new compounds wit...