- Convergent and selective synthesis of pyrrolidinones, piperidinones, dihydropyridinones and pyridinols from a common intermediate - Potential precursors of bioactive products
Titanium-mediated cyclopropanation of natural and unnatural β-amino acid derivatives provides azabicyclo[3.1.0]hexan-1-ols as mixtures of diastereomers that are separable by silica-gel chromatography. Depending on the ring cleavage procedure employed, these compounds lead efficiently to diverse intermediates for the synthesis of pharmaceuticals. Thus, depending on the experimental conditions, basic treatment can furnish racemic pyrrolidinones as a mixture of diastereomers and piperidinones. In contrast, the synthesis of optically active dihydropyridinones was achieved through a one-pot FeCl 3/AcONa reaction or performed by using bis(sym-collidine)iodine hexafluorophosphate. Furthermore, whereas the palladium-mediated hydrogenolysis of these dihydropyridinones furnished both chiral piperidinones and original pyridinols, a CeIV-promoted radical process yielded chiral tricyclic piperidinones. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Jida, Mouhamad,Ollivier, Jean
experimental part
p. 4041 - 4049
(2009/04/14)
- 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.
- Jida, Mouhamad,Guillot, Régis,Ollivier, Jean
p. 8765 - 8767
(2008/03/18)