Gurram Mahender

A mild, highly selective and remarkably easy procedure for deprotection of aromatic acetates using ammonium acetate as a neutral catalyst in aqueous medium

Ammonium acetate was found to catalyze efficiently the selective deprotection of aromatic acetates in the presence of various sensitive functionalities in aqueous methanol under neutral conditions at room temperature to yield the corresponding phenols in excellent yields. The method has been utilized for deprotection of acetates of several naturally occurring bioactive phenolic compounds and for preparation of venkatasin, a natural coumarino-lignan, from the anticancer compound cleomiscosin A.

A simple, mild and efficient procedure for selective cleavage of prenyl esters using silica-supported sodium hydrogen sulphate as a heterogenous catalyst ☆

Prenyl esters were selectively and efficiently cleaved under slightly acidic reaction conditions using silica-supported sodium hydrogen sulfate as a heterogenous catalyst at room temperature to regenerate the parent carboxylic acids in very high yields.

A convenient, rapid, highly selective and eco-friendly method for deprotection of aryl acetates using silica gel supported ammonium formate under microwave irradiation

Several aryl acetates were rapidly and selectively deprotected to the corresponding phenols in excellent yields using silica gel supported ammonium formate under microwave irradiation. The process is environmentally benign.

Synthesis of coumarins via a Pechmann condensation using heterogeneous catalysts

The synthesis of coumarins via a Pechmann condensation involving the reaction between phenols and ethyl acetoacetate has been carried out using two heterogeneous catalysts, NaHSO4.SiO2 and silica chloride under solvent free conditions, thus avoiding acidic waste

(3R*,6S*,6aR*,9S*,9aS*)-6,6a,9-Trihydroxy-3,6,9a-trimethyl­perhydro­azuleno[1,2-b]furan-2-one

The title compound, C15H24O5, was isolated from the flowers of Parthenium hysterophorus. The crystal structure determination confirms the relative stereochemistry unambiguously. The packing is stabilized by O—H⋯O hydrogen bonding.