Avula Satya Kumar

New bioactive macrocyclic diterpenoids from Jatropha multifida.

Two new macrocyclic diterpenoids, multifidanol (1) and multifidenol (2) along with several known compounds have been isolated from the stem of Jatropha multifida. The structures of the new compounds were established from the extensive studies of their 1D and 2D NMR spectra. The cytotoxic and antimicrobial activities of these two constituents were examined.

Efficient Thiocyanation of Indoles Using Para-Toluene Sulfonic Acid

Treatment of indoles with ammonium thiocyanate in the presence of para-toluene sulfonic acid afforded the corresponding 3-thiocyano indoles at room temperature in excellent yields.

A new macrocyclic diterpenoid from Jatropha multifida.

A new diterpenoid, 15-epi-(4E)-jatrogrossidentadione acetate, along with several known constituents has been isolated from the stem of Jatropha multifida. The structure of the new compound was settled by a detailed analysis of its 1D- and 2D-NMR spectra.

Stereoselective Synthesis of β-Amino Ketones: A Three-Component Mannich-Type Reaction of Aromatic Aldehydes, Anilines, and Cyclohexanone Using Amberlyst-15

Abstract A three-component Mannich-type reaction of aromatic aldehydes, anilines, and cyclohexanone in the presence of Amberlyst-15 affords the corresponding β-amino ketones in good yields at room temperature. The conversion is highly diastereoselective, favoring the formation of anti-isomers.

Rapid, efficient and selective conjugate addition of thiols to α, β-unsaturated carbonyl compounds using silica supported sodium hydrogen sulfate under solvent-free conditions†

The conjugate addition of thiols to α, β-unsaturated carbonyl compounds was carried out rapidly (within 2–5 min) and selectively in the presence of silica supported sodium hydrogen sulfate (NaHSO4·SiO2) to form the corresponding Michael adducts in excellent yields (86–95%) at room temperature and under solvent-free conditions. †Part 157 in the series, ‘Studies on novel synthetic methodologies’

A distinct novel approach for the synthesis of 3-indolyl-methanamines starting from indoles, aldehydes and nitrobenzenes in water

3-Indolyl-methanamines have efficiently been synthesized by the treatment of indoles with aldehydes and nitrobenzenes using indium in aqueous HCl at room temperature. The products are formed in excellent yields (91–98%) within a short period of time (30–45 min). Bisindolyl methanes have not been obtained under the present reaction conditions.

Stereoselective Total Synthesis of Proposed Structure of Stagonolide D

The stereoselective total synthesis of the proposed structure of naturally occurring nonenolide stagonolide D has been achieved using D-mannitol as the starting material. The latter has been utilized for the preparation of both the olefinic alcohol segment and the olefinic acid segment of the target molecule. The synthetic sequence involves asymmetric epoxidation and ring-closing metathesis as the key steps.