Camphoric Acid → rel-(1R,3S)-1,2,2-Trimethyl-1,3-cyclopentanedimethanol

A solution of (1R,3S)-1,2,2-trimethylcyclopentane-1,3-dicarboxylic acid (26.25 g, 131 mmol) in THF (400 mL) was cooled in an ice bath (10° C.) and to this was added 1M LiAlH4/THF (328 mL, 328 mmol), dropwise over 1 h. The ice bath was removed and the white slurry was stirred for 5 h at room temperature and 17 h at reflux. After cooling to room temperature, the mixture was diluted with Et2O (500 mL), cooled in an ice bath and carefully quenched with water (12.2 mL), 15% NaOH (12.2 mL) and water (36.7 mL). After stirring for 30 min at room temperature, the white slurry was filtered through a pad of CELITE®, then dried (Na2SO4), filtered and concentrated to give ((1R,3S)-1,2,2-trimethylcyclopentane-1,3-diyl)dimethanol (21.665 g, 126 mmol, 96% yield) as a white solid. 1H NMR (500 MHz, CDCl3) δ: 3.73 (1 H, dd, J=10.2, 5.3 Hz), 3.58 (1 H, d, J=10.7 Hz), 3.51 (1 H, dd, J=10.1, 8.5 Hz), 3.46 (1 H, d, J=10.7 Hz), 2.04-2.12 (1 H, m), 1.89-1.99 (1 H, m), 1.55-1.64 (1 H, m), 1.31-1.41 (2 H, m), 1.22 (2 H, brs), 1.02 (3 H, s), 1.01 (3 H, s), 0.78 (3 H, s).

1. customThe ice bath was removed
2. temperatureat reflux
3. temperatureAfter cooling to room temperature
4. additionthe mixture was diluted with Et2O (500 mL)
5. temperaturecooled in an ice bath
6. customcarefully quenched with water (12.2 mL), 15% NaOH (12.2 mL) and water (36.7 mL)
7. stirringAfter stirring for 30 min at room temperature
8. filtrationthe white slurry was filtered through a pad of CELITE®
9. dry with materialdried (Na2SO4)
10. filtrationfiltered
11. concentrationconcentrated

ORDレコード

ord-dc9e7c0082d34a1f9bd7ed784d399003

出典データセット

uspto-grants-2012_03

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US08129398B2