Azabicyclo[3.1.0]hexane-1-ols as frameworks for the asymmetric synthesis of biologically active compounds

Azabicyclo[3.1.0]hexane-1-ols, easily obtained by Ti(IV)-mediated cyclopropanation of amino acid derivatives, constitute versatile, and unprecedented intermediates for the asymmetric synthesis of pharmacologically active products. Indeed, through selective rearrangement, these compounds undergo unusual ring cleavage to lead to pyrrolidinones. Fe(III)-promoted ring opening followed by basic dehydrohalogenation furnishes optically active dihydropyridinones, while Ce(IV)-promoted ring opening provides chiral tricyclopiperidinones via a radical process.