Rattan L. Sharma

Alum-Catalyzed One-Pot Solventless Synthesis of 1,5-Benzodiazepines

Alum [KAl(SO4)2∙12H2O] was found to be an efficient, non-toxic, cheap, and environmentally benign catalyst for the synthesis of 1,5-benzodiazepines, in good to excellent yields, from the condensation of 1 mole of o-phenylenediamine with 2 moles of ketone under solvent-free conditions.

A new iridoid glycoside from Vitex negundo Linn (Verbenacea).

Five compounds have been isolated from the leaves of Vitex negundo Linn (Verbenacea) and their structures established by spectral analysis. Compound 1 has been identified and characterised as a new iridoid with a novel structure which has never before been reported in literature from Vitex or any other source. Its structure has been established as 1,4a,5,7a-tetrahydro-1-β-D-glucosyl-7-(3′,4′-dihydroxybenzoyloxymethyl)-5-ketocyclopenta[c]pyran-4-carboxylic acid. Other compounds, 2, 3, 4 and 5, have been identified as luteolin-7-O-β-D glucoside, nishindaside, negundoside, and agnuside, respectively. Compound 2, a flavone-O-glycoside, is being reported from this plant for the first time, and compounds 3, 4 and 5 are structurally known iridoids.

Entrapment and kinetic resolution of stabilized axial and equatorial conformers of spiro-β-lactams.

The facile synthesis of the stabilized axial and equatorial conformers of spiro-β-lactams was achieved via entrapment of cyclohexanone imines (Schiff bases) with acetoxyacetyl chloride in a [2 + 2]-cycloaddition reaction followed by their kinetic resolution. The immobilization of the racemic substrates on an inert solid support significantly reduced the reaction time and improved the enantioselectivity of conformers during kinetic resolution. The mechanism of the formation of the spiro-β-lactams was explored using B3LYP/6-31+G* level quantum chemical calculations.