Regiodivergent epoxide opening (REO) via electron transfer: control elements

The first regiodivergent opening of unbiased epoxides (REO) providing the ring-opened products in high enantiomeric excess from racemic and exceptionally high enantiomeric excess from enantioenriched substrates in a double asymmetric process has been devised. It constitutes a more general case of the very important enantioselective openings of meso-epoxides. The dependence of the selectivity of ring opening on the epoxide’s substitution pattern was studied.

Figure optionsDownload as PowerPoint slide

tert-Butyl 3-((4S,5R)-3-propyloxiran-2-yl)propanoateC12H22O3Ee = 80%[α]D=-6.4[α]D=-6.4 (c 0.8, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (4S,5R)

tert-Butyl 3-((4S,5R)-3-pentyloxiran-2-yl)propanoateC14H26O3Ee = 88%[α]D=-11.9[α]D=-11.9 (c 0.9, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (4S,5R)

tert-Butyl 2,2-dimethyl-3-((4S,5R)-3-pentyloxiran-2-yl)propanoateC16H30O3Ee = 85%[α]D=-0.3[α]D=-0.3 (c 2.0, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (4S,5R)

(R)-tert-Butyl 4-hydroxyoctanoateC12H24O3Ee = 94%[α]D=+0.7[α]D=+0.7 (c 0.9, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(R)-tert-Butyl 5-hydroxyoctanoateC12H24O3Ee = 99%[α]D=-0.5[α]D=-0.5 (c 0.7, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(R)-tert-Butyl 4-hydroxynonanoateC13H26O3Ee = 79%[α]D=+1.0[α]D=+1.0 (c 0.2, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(R)-tert-Butyl 5-hydroxynonanoateC13H26O3Ee = 79%[α]D=-1.0[α]D=-1.0 (c 0.1, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(R)-tert-Butyl 4-hydroxydecanoateC14H28O3Ee = 98%[α]D=+1.5[α]D=+1.5 (c 0.6, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(R)-tert-Butyl 4-hydroxydecanoateC14H28O3Ee = 98%[α]D=+1.2[α]D=+1.2 (c 0.4, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(S)-tert-Butyl 5-cyclohexyl-4-hydroxypentanoateC15H28O3Ee = 70%[α]D=-6.0[α]D=-6.0 (c 1.6, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (S)

(S)-tert-Butyl 5-cyclohexyl-5-hydroxypentanoateC15H28O3Ee = 94%[α]D=-10.5[α]D=-10.5 (c 0.5, CH3OH)Source of chirality: asymmetric synthesisAbsolute configuration: (S)

(R)-tert-Butyl 4-hydroxy-2,2-dimethyldecanoateC16H32O3Ee = 99%[α]D=+3.2[α]D=+3.2 (c 2.0, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(R)-tert-Butyl 4-hydroxy-2,2-dimethyldecanoateC16H32O3Ee = 94%[α]D=+0.6[α]D=+0.6 (c 1.5, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(R)-6-Propyltetrahydro-2H-pyran-2-oneC8H14O2Ee = 81%[α]D=+33.3[α]D=+33.3 (c 1.0, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(R)-5-Butyldihydrofuran-2(3H)-oneC8H14O2Ee = 94%[α]D=-40.2[α]D=-40.2 (c 0.4, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(S)-6-Butyltetrahydro-2H-pyran-2-oneC9H16O2Ee = 79%[α]D=-36.4[α]D=-36.4 (c 4.0, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(S)-5-Pentyldihydrofuran-2(3H)-oneC9H16O2Ee = 79%[α]D=+28.3[α]D=+28.3 (c 4.5, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (S)

(S)-6-Pentyltetrahydro-2H-pyran-2-oneC10H18O2Ee = 89%[α]D=+41.6[α]D=+41.6 (c 1.7, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (S)

(R)-5-Hexyldihydrofuran-2(3H)-oneC10H18O2Ee = 98%[α]D=-33.0[α]D=-33.0 (c 0.9, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(R)-3,3-Dimethyl-6-pentyltetrahydro-2H-pyran-2-oneC12H22O2Ee = 94%[α]D=-24.9[α]D=-24.9 (c 2.0, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(R)-5-Hexyl-3,3-dimethyldihydrofuran-2(3H)-oneC12H22O2Ee = 62%[α]D=+13.7[α]D=+13.7 (c 2.0, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(S)-6-(Butoxymethyl)tetrahydro-2H-pyran-2-oneC10H18O3Ee = 92%[α]D=-46.0[α]D=-46.0 (c 3.1, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (S) tentatively

(S)-5-(2-Butoxyethyl)dihydrofuran-2(3H)-oneC10H18O3Ee = 81%[α]D=+9.6[α]D=+9.6 (c 2.5, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R) tentatively