Chaetochromins B, C and D, bis(naphtho-.GAMMA.-pyrone) derivatives from Chaetomium gracile.

Synthesis of some derivatives of dimedone, gamma pyrone and barbituric acid.

Aim: Dimedone , gamma pyrone and barbituric acid and their derivatives have also been found to be very important from their application point of view. Thus our aim was to prepare more derivatives from them. Method : Dimedone , gamma pyrone and barbituric acid have been treated with dimethyl sulphoxide and acetic anhydride reagent under varying temperature conditions in order to get more compoun...

[BMIm]BF4-LiCl: An effective catalytic system for the synthesis of pyrano[3,2-c]chromene and pyrano[4,3-b]pyrone derivatives

An efficient and green method for the synthesis of pyrano[3,2-c]chromene or pyrano[4,3-b]pyrone derivatives is described by using a three-component condensation process of malononitrile, aldehyde, and 4-hydroxycoumarine or 4-hydroxypyrone in [BMIm]BF4-LiCl as an ionic liquid.

[BMIm]BF4-LiCl: An effective catalytic system for the synthesis of pyrano[3,2-c]chromene and pyrano[4,3-b]pyrone derivatives

An efficient and green method for the synthesis of pyrano[3,2-c]chromene or pyrano[4,3-b]pyrone derivatives is described by using a three-component condensation process of malononitrile, aldehyde, and 4-hydroxycoumarine or 4-hydroxypyrone in [BMIm]BF4-LiCl as an ionic liquid.

Antibacterial activities of erythromycins A, B, C, and D and some of their derivatives.

The MICs of erythromycins A, B, C, and D and some of their derivatives were determined against 21 gram-positive and 15 gram-negative microorganisms. Antibacterial activity was confined to gram-positive and very few gram-negative bacteria. Erythromycin B was somewhat less active than erythromycin A, and erythromycin C and D showed about half that activity or even less. Most other derivatives had...

( a ) Φ ( a , B ) Φ Φ ( B , C ) ( C , D )