| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1347229 | Tetrahedron: Asymmetry | 2014 | 7 Pages |
The preparation of chiral building blocks, suitable for use in the enantioselective total synthesis of kauranoids and ent-kauranoids, is reported herein. The pig liver esterase-catalyzed asymmetric hydrolysis of dimethyl 3,3-dimethyl-2-methylenecyclohexane-1,2-dicarboxylate, a malonate-type prochiral diester, afforded the corresponding half-ester in 96% yield and with 99% enantiomeric excess. The absolute configuration of the half-ester was determined by X-ray crystallographic analysis of its derivative and its enantiodivergent transformations are also described herein.
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(R)-1-Methoxycarbonyl-3,3-dimethyl-2-methylenecyclohexane-1-carboxylic acidC12H18O4[α]D23=-18.6 (c 0.80, CHCl3) 99% eeSource of chirality: pig liver esteraseAbsolute configuration: (R)
(S)-Methyl 3,3-dimethyl-2-methylene-1-phenylaminooxycarbonylcyclohexane-1-carboxylateC18H23NO4[α]D22=+77.7 (c 0.39, CHCl3) 99% eeSource of chirality: pig liver esteraseAbsolute configuration: (S)
(S)-Methyl 1-(4-bromo-2-methylphenylaminooxycarbonyl)-3,3-dimethyl-2-methylenecyclohexane-1-carboxylateC19H24BrNO4[α]D23=+100.7 (c 0.60, CHCl3) 99% eeSource of chirality: pig liver esteraseAbsolute configuration: (S)
(R)-Methyl 1-hydroxymethyl-3,3-dimethyl-2-methylenecyclohexane-1-carboxylateC12H20O3[α]D23=-61.9 (c 1.5, CHCl3) 99% eeSource of chirality: pig liver esteraseAbsolute configuration: (R)
(3aS,7aR)-7a-Hydroxymethyl-4,4-dimethylhexahydroisobenzofuran-1(3H)-oneC11H18O3[α]D23=-19.4 (c 0.17, CHCl3) 99% eeSource of chirality: pig liver esteraseAbsolute configuration: (S,R)
(S)-1-tert-Butyl 1-methyl 3,3-dimethyl-2-methylenecyclohexane-1,1-dicarboxylateC12H20O3[α]D19=-6.8 (c 0.65, CHCl3) 99% eeSource of chirality: pig liver esteraseAbsolute configuration: (S)
(S)-1-tert-Butoxycarbonyl-3,3-dimethyl-2-methylenecyclohexane-1-carboxylic acidC12H20O3[α]D20=+7.6 (c 0.75, CHCl3) 99% eeSource of chirality: pig liver esteraseAbsolute configuration: (S)
(S)-tert-Butyl 1-hydroxymethyl-3,3-dimethyl-2-methylenecyclohexane-1-carboxylateC12H20O3[α]D20=+28.8 (c 0.21, CHCl3) 99% eeSource of chirality: pig liver esteraseAbsolute configuration: (S)
(S)-Methyl 1-hydroxymethyl-3,3-dimethyl-2-methylenecyclohexanecarboxylateC11H18O3[α]D20=+60.0 (c 0.21, CHCl3) 99% eeSource of chirality: pig liver esteraseAbsolute configuration: (S)
