Diastereoselective synthesis of deprotectable isoxazolidines

Isoxazolidine: A Privileged Scaffold for Organic and Medicinal Chemistry

The isoxazolidine ring represents one of the privileged structures in medicinal chemistry, and there have been an increasing number of studies on isoxazolidine and isoxazolidine-containing compounds. Optimization of the 1,3-dipolar cycloaddition (1,3-DC), original methods including electrophilic or palladium-mediated cyclization of unsaturated hydroxylamine, has been developed to obtain isoxazolidines. Novel reactions involving the isoxazolidine ring have been highlighted to accomplish total synthesis or to obtain bioactive compounds, one of the most significant examples being probably the thermic ring contraction applied to the total synthesis of (±)-Gelsemoxonine. The unique isoxazolidine scaffold also exhibits an impressive potential as a mimic of nucleosides, carbohydrates, PNA, amino acids, and steroid analogs. This review aims to be a comprehensive and general summary of the different isoxazolidine syntheses, their use as starting building blocks for the preparation of natural compounds, and their main biological activities.

Regio- and diastereoselectivity of the 1,3-dipolar cycloaddition of α-aryl nitrone with methacrolein. A theoretical investigation

The mechanism, regio- and diastereoselectivity of the 1,3-dipolar cycloaddition of N-iso-propyl,α-(4-trifluoromethyl)-phenyl nitrone with methacrolein yielding the isoxazolidine cycloadduct has been studied at the B3LYP/6-31G(d) level of theory.