(S)-(+)-3-hydroxy-2,2-dimethylcyclohexanone
bp 85–87°C at 3.7 mm, [α]21D + 23.0° (CHCl3, c 2.0)
The spectral properties of (S)-(+)-3-hydroxy-2,2-dimethylcyclohexanone are as follows:
IR vmax (film) cm−1: 3470 (s), 1705 (s), 1120 (m), 1055 (s), 985 (s), 965 (m);
1H NMR (250 MHz, CDCl3) δ: 1.11 (s, 3 H), 1.15 (s, 3 H), 1.60–1.71 (m, 1 H), 1.76–1.86 (m, 1 H), 1.96–2.05 (m, 2 H), 2.16 (br s, 1 H), 2.35–2.45 (m, 2 H), 3.69 (dd, 1 H, J = 7.6, 2.9);
13C NMR (76 MHz, CDCl3) δ: 19.7, 20.7, 22.9, 29.0, 37.3, 51.3, 77.8, 215.3.
The optical purity of (S)-(+)-3-hydroxy-2,2-dimethylcyclohexanone can be determined by HPLC analysis.
The (S)-α-methoxy-α-trifluoromethylphenylacetate (MTPA ester) is prepared according to the reported procedure:3 HPLC analysis (Column, Nucleosil® 50-5, 25 cm × 4.6 mm; eluant, hexane : THF = 30 : 1, 1.03 mL/min; detected at UV 256 nm) retention time 35.6 min (98.0–99.4%) and 29.6 min (0.6–(2.0%). Therefore, the optical purity is determined to be 96.0–98.8% ee.
Analysis of the MTPA ester of this product by 250 MHz 1H NMR and capillary GLC (12.5 m, 5% methyl silicone column) failed to detect any more of the minor diastereomer than would have been expected from the purity (98% ee) of the MTPA-Cl employed.
NOTE….Intermediate is
2,2-dimethylcyclohexane-1,3-dione bp 92–97°C (4 mm)
The spectra are as follows: 1H NMR (250 MHz, CDCl3) δ: 1.29 (s, 6 H), 1.93 (5 lines, 2 H, J = 6.5), 2.67 (t, 4 H, J = 6.9); 13C NMR (76 MHz, CDCl3) δ: 18.1, 22.3, 37.4, 61.8, 210.6.
Natural products synthesized from (S)-3-hydroxy-2,2-dimethylcyclohexanone
References and Notes
- Department of Agricultural Chemistry, The University of Tokyo, Yayoi 1-1-1, Bunkyo-Ku, Tokyo 113, Japan.
- Mekler, A. B.; Ramachandran, S.; Swaminathan, S.; Newman, M. S. Org. Synth., Coll. Vol. V 1973, 743, 3.
- Dale, J. A.; Mosher, H. S. J. Am. Chem. Soc. 1973, 95, 512.
- Kieslich, K. “Microbial Transformations of Non-Steroid Cyclic Compounds;” Georg Thieme; Stuttgart, 1976, pp. 28–31.
- Lu, Y.; Barth, G.; Kieslich, K.; Strong, P. D.; Duax, W. L.; Djerassi, C. J. Org. Chem. 1983, 48, 4549.
- Mori, K.; Mori, H. Tetrahedron 1985, 41, 5487.
- Yanai, M.; Sugai, T.; Mori, K. Agric. Biol. Chem. 1985, 49, 2373.
- Mori, K.; Watanabe, H. Tetrahedron 1986, 42, 273.
- Mori, K.; Nakazono, Y. Tetrahedron 1986, 42, 283.
- Mori, K.; Mori, H.; Yanai, M. Tetrahedron 1986, 42, 291.
- Mori, K.; Tamura, H. Tetrahedron 1986, 42, 2643.
- Sugai, T.; Tojo, H.; Mori, K. Agric. Biol. Chem. 1986, 50, 3127.
- Mori, K.; Mori, H. Tetrahedron 1986, 42, 5531.
- Mori, K.; Mori, H. Tetrahedron 1987, 43, 4097.
- Mori, K.; Komatsu, M. Liebigs Ann. Chem. 1988, 107.
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