Synthesis of enantiomerically enriched α,α-disubstituted β,γ-epoxy esters using hydrolytic kinetic resolution catalyzed by salenCo(III)

Novel α,α-disubstituted epoxy esters were prepared in enantiopure form by hydrolytic kinetic resolution (HKR) of the corresponding racemic mixtures using chiral salenCo(III) as catalyst. The methodology provides a convenient route to enantioenriched β,γ-epoxy esters 2a, 2c and 2d.

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Ethyl 2,2-dimethyl-3,4-epoxybutanoateC8H14O3Ee = >99%[α]D23=+16.1 (c 0.98, CH2Cl2)Source of chirality: hydrolytic kinetic resolution, salenCo(III)Absolute configuration: (S)

Ethyl, 2,2-cyclopropyl-3,4-epoxybutanoateC10H16O3Ee = >99%[α]D23=-2.1 (c 1.05, CH2Cl2)Source of chirality: hydrolytic kinetic resolution, salenCo(III)Absolute configuration: (R)

Ethyl 2,2-diethyl-3,4-epoxybutanoateC10H18O3Ee = 98%[α]D22=-58.1 (c 0.51, CH2Cl2)Source of chirality: hydrolytic kinetic resolution, salenCo(III)Absolute configuration: (R)