New chiral monoaza-15-crown-5 compounds anellated to methyl-4,6-O- benzylidene-α-D-mannopyranosides 2a-f have been synthesized. These crown ethers showed significant asymmetric induction as phase-transfer catalysts in the Michael addition of 2-nitropropane to chalcone (92% ee), in the Darzens condensation of phenacyl chloride with benzaldehyde (45% ee) and in the epoxidation of chalcones with tert-butyl-hydroperoxide (82% ee). The enantioselectivity was effected by the substituents at the nitrogen atom of the crown ring. The absolute configurations of epoxyketones 10 were determined by CD spectroscopy.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry