RESUMEN
A thermodynamically controlled resolution has allowed for the generation of diastereomerically enriched complexes, by chirality transfer from an enantiopure building block to a dynamically racemic biaryl derivative. A switchable sense of induction could be achieved depending on the substituents of the chiral block.
RESUMEN
[reaction: see text] A practical synthesis of Shi's diester 3 for catalytic asymmetric epoxidations has been developed. The catalyst has been prepared in multigram quantities from D-fructose in four steps with a 66% overall yield. Efficiency, cost, and selectivity aspects of the reagents involved for its preparation have been taken care of during its preparation. The workup procedures have been simplified to the bare minimum, rendering a very practical preparation method. The well-known high efficiency of this catalyst 3 in the epoxidation of alpha,beta-unsaturated carbonyl compounds has also proved to be high in unfunctionalized alkenes.