1. [3+2] Route to Quaternary Oxaprolinol Derivatives as Masked Precursors of Disubstituted β3,β3-Amino Aldehyde
- Author
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Gilles Dujardin, Arnaud Martel, Amelle Mankou Makaya, Mathieu Y. Laurent, Anne Beauchard, and Pavlo Shpak-Kraievskyi
- Subjects
chemistry.chemical_classification ,Chiral auxiliary ,Bicyclic molecule ,010405 organic chemistry ,Stereochemistry ,Organic Chemistry ,Enantioselective synthesis ,010402 general chemistry ,01 natural sciences ,Aldehyde ,Cycloaddition ,0104 chemical sciences ,Stereocenter ,chemistry.chemical_compound ,chemistry ,Physical and Theoretical Chemistry ,Chemoselectivity ,Bond cleavage - Abstract
Bicyclic isoxazolidines displaying one or two quaternary stereocenter(s) were formed starting from functional cyclic ketonitrones equipped with a phenyl glycinol chiral auxiliary. The products were engaged in stereocontrolled 1,3-dipolar cycloaddition reactions with a range of electron-rich and electron-poor dipolarophiles. A new reductive removal of the phenyl glycinol chiral auxiliary was introduced and was shown to afford chemoselectively a quaternary isoxazolidine derivative (of oxaprolinol-type) without cleaving the N–O isoxazolidine bond. Keeping the aldehyde function masked as a cyclic pseudo-acetal, the liberated oxy-amine function was shown to be available for a pseudo-peptide coupling with various N-protected amino acids. The isoxazolidine ring was opened by a reductive N–O bond cleavage, giving a pseudo-dipeptide that was C-terminated with an aldehyde function.
- Published
- 2015
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