New chiral monoaza-15-crown-5 type macrocycles anellated to 3,4-O-isopropylidene-β-L-arabinopyranose (5a-b), to β-L- arabinopyranose (6) and to 3,4-O-benzyliden-β-L-arabinopyranose (11) have been synthesized. The cation binding ability of the new lariat ethers was evaluated by the picrate extraction method in liquid-liquid system. Some representatives of these crown ethers showed moderate asymmetric induction as chiral phase transfer catalysts, among them 11 with a benzylidene group proved to be the most efficient one inducing 64% ee in the Michael addition of 2-nitropropane to chalcone and 61% ee in the addition of diethyl acetamidomalonate to trans-β-nitrostyrene. An induction of 65% ee was observed in the epoxidation of a chalcone analogue with tert-butyl hydroperoxide in the presence of catalyst 5a.
ASJC Scopus subject areas
- Organic Chemistry