Batchu Venkateswara Rao

Synthesis of (±) Fredericamycin A

Abstract The synthesis of Fredericamycin A (1) has been achieved by subjecting the 1,3-dione (14) to an unusual 5- endo trigonal radical cyclization followed by reductive elimination of the halogen in 15 and subsequent demethylation.

Synthesis of (±) fredericamycin A

A total synthesis of fredericamycin A (1) is described, in which a novel radical cyclisation approach is used to build the spiro[4.4]nonane system. The supporting studies with experimental details are reported

DDQ-Promoted Benzylic/Allylic sp3 C–H Activation for the Stereoselective Intramolecular C–N Bond Formation: Applications to the Total Synthesis of (−)-Codonopsinine, (+)-5-epi-Codonopsinine, (+)-Radicamine B, and (−)-Codonopsinol

This is the first report on an intramolecular C-N bond formation of an amide-tethered benzylic/allylic system using DDQ under neutral conditions which has been successfully applied to the total synthesis of naturally occurring pyrolidine alkaloids. The key steps for the synthesis of corresponding precursors involve Julia-Kociensky olefination/cross-metathesis and dihydroxylation reactions, and this methodology is also extended to the ω-unsaturated N-sulfanilamide to furnish piperidines.

Oxazolidinone derivatives: cytoxazone-linezolid hybrids induces apoptosis and senescence in DU145 prostate cancer cells.

In this study, we report the synthesis of novel oxazolidinone derivatives derived from linezolid 3 having p-methoxyphenyl group at C-4 position. In vitro evaluation for their anticancer activity toward cultured A549, DU145, HELA, and MCF7 were carried out. The series of compounds prepared displayed wide range of cytotoxicity in MTT assays (10-70 μM) across the cell lines tested. Of the all tested compounds 16 and 17 displayed good anticancer potential against A549 (lung) and DU145 (prostate) cancer cells. Further, to determine their anticancer potential, in the present study we have assessed effect of 17 on DU145 cells growth in in vitro assays. The results clearly demonstrated that the exposure of DU145 cells to 17 inhibits cell proliferation and induces apoptosis by activation of caspase-3 and -9. Long term exposure of DU145 cells to 17 induced cellular senescence confirmed by senescence marker β-galactosidase staining of cells on post exposure to 17. The results from this current report support that the oxazolidinone derivatives with ethyl and acryl substitutions showed promising anticancer activity which will be helpful to develop further novel anticancer agents with better therapeutic potential.

Concise stereoselective synthesis of 5-hydroxy carba-β-D-rhamnose, carba-β-D-rhamnose, (-)-gabosine O, and carba-α-D-rhamnose

ABSTRACT A divergent approach was developed for the synthesis of 5-hydroxy carba-β-D-rhamnose 1, carba-β-D-rhamnose 2, (-)-gabosine O 3, and carba-α-D-rhamnose 4 starting from D-ribose using ring closing metathesis (RCM). GRAPHICAL ABSTRACT

Palladium-Catalyzed Double Allylation of Sugar-Imines by Employing Tamaru-Kimura's Protocol: Access to Unnatural Iminosugars

Conversion of vinyl pyranosylamine and vinyl furanosylamines to 2,6- and 2,5-disubstituted pyrrolidine and piperidine iminosugars, respectively, in one pot was developed using Kimura and Tamarus procedure, where a Pd salt in the presence of Et2Zn was used for the domino reaction. In this procedure, double allylation, which involves nucleophilic allylation-heterocyclization, took place to give desired nitrogen heterocycles. This strategy was further elaborated to synthesize some unnatural deoxycalystegines, hydroxylated pyrrolidines, piperidines, and indolizidine analogues.