ORGN 347 |
| In recent years, 1,3-dipolar cycloaddition reaction has been applied as a useful methodology for the synthesis of various heterocycles. The synthesis of pyrazoline derivatives has received much attention due to their potential to exhibit various biological activities viz., anti-inflammatory, analgetics, herbicidal, virucidal, and insecticidal activity. Nitrile imines are a class of 1,3-dipoles which offer a vast scope in the synthesis of 5-membered pyrazoles and many methods for pyrazole synthesis have been developed. The readily synthesized highly funtionalized alkene, when subjected to [2+3]-dipolar cycloaddition reaction with in situ generated aromatic nitrile imines, affored the corresponding desired 5,5-disubstituted pyrazoline cycloadduct as a single regioisomer. Subsequent intramolecular cyclization/methylation carried out in one pot by employing suitable bases afforded the regiomeric mixture of spiropyrazolines, which resulted from the O-alkylation of both spiropyrazoline intermediate enolates. Our interests in this area include approaches to the syntheses of various potentially biologically active spiropyrazoline molecules that may have applications in breast cancer. |
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Heterocycles and Aromatics, Molecular Recognition and Self Assembly
8:00 PM-10:00 PM, Tuesday, April 8, 2008 Morial Convention Center -- Hall A, Poster
Division of Organic Chemistry |