Catalytic enantioselective rearrangement of meso-epoxides mediated by chiral lithium amides in the presence of excess cross-linked polymer-bound lithium amides

Insoluble polymer-bound achiral lithium dialkylamides were prepared from the corresponding cross-linked polymer-bound amines and butyllithium. The polymer-bound achiral reagent was applied to a catalytic enantioselective rearrangement of meso-epoxides as an in situ regenerating agent of a chiral lithium amide. The efficiency of the catalytic system was improved, and chiral allylic alcohol derivatives were obtained in high enantiomeric excesses by using excess polymer-bound reagents and a sub-stoichiometric amount of chiral lithium amide, prepared from (2S,3aS,7aS)-2-(pyrrolidin-1-ylmethyl)octahydroindole. The reaction was successfully applied in the synthesis of (1S,4R)-4-benzoylamino-2-cyclopentenol, a useful chiral synthetic intermediate for carbocyclic nucleosides, in 97% ee.