A novel, two-step, mild and simple synthesis of β-, γ and δ-oxo esters from ω-nitro esters

Abstract

Since the first example of the Claisen condensation was discovered more than a century ago, β-oxo esters have become one of the most important intermediates in organic synthesis. In addition, y- and δ-oxo esters are highly useful compounds because five- or six-membered carbocycles, and various heterocycles such as lactones, β-lactam antibiotics, isoquinolines and lactonic sex pheromones, are readily accessible from them. Although they have been synthesized by a variety of approaches, several of the existing methods follow lengthy procedures and/or involve expensive chemicals. [excerpt]