(2R)-3-cyclohexyl-2-methylpropanoic acid

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of α(R)-methylcyclohexane-propionic acid (2.4 g, 14 mmol) in dry CH2Cl12 (30 mL) was added DMF (1 drop) and oxalyl chloride (2 g, 15 mmol). After 2 h at room temperature, the mixture was concentrated. The residue was dissolved in Et2O (10 mL). This solution was filtered. The filtrate was concentrated to provide α(R)-methylcyclohexanepropionic acid chloride as a clear yellow liquid (2.6 g, 98% yield). 1H NMR (400 MHz, CDCl3) 3.02-2.91 (m, 1H), 1.80-1.63 (m, 6H), 1.39-1.10 (m, 5H), 1.28 (d, J=7 Hz, 3H), 0.99-0.85 (m, 2H). This material was used without further purification in the coupling reaction described in the following example. the mixture was concentrated The residue was dissolved in Et2O (10 mL) This solution was filtered The filtrate was concentrated

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A mixture of α(R)-methylbenzenepropionic acid (3.0 g, 18 mmol) and 5% rhodium on alumina (800 mg) in methanol (100 mL) was shaken under 40 p.s.i. of H2 on a Parr hydrogenation apparatus. After 15 h, the mixture was filtered through diatomaceous earth and concentrated to afford α(R)-methylcyclohexanepropionic acid as a clear liquid (2.4 g, 77%). 1H NMR (CDCl3) δ 2.62-2.53 (m, 1H), 1.79-1.59 (m, 6H), 1.38-1.16 (m, 5H), 1.17 (d, J=7 Hz, 3H), 0.95-0.83 (m, 2H). the mixture was filtered through diatomaceous earth concentrated