Methanol → Methyl (2S)-2-hydroxy-4-methylpentanoate

Temperature

0 °C

To a solution of (S)-2-hydroxy-4-methylpentanoic acid (3.0 g, 22.7 mmol) in methanol was added TMS.CH2N2 (2M in hexanes, 34 mL, 17 mmol) dropwise, at 0° C., over 20 min. The reaction mixture was stirred at 0° C. for 1 h. The solution was concentrated using a bath temperature of 20° C. and vacuum greater than 50 mm Hg. Purification via silica gel chromatography using 2-100% EtOAc in hexanes gave the ester as a yellow oil (2.14 g, 14.5 mmol, 64% yield). 1H NMR (400 MHz, DMSO-d6) δ 5.13 (s, 1H), 4.1-4.0 (m, 1H), 3.81 (s, 3H), 1.6-1.5 (m, 1H), 2.35-2.20 (m, 2H), 1.05-0.84 (m, 6H).

1. concentrationThe solution was concentrated
2. customtemperature of 20° C. and vacuum greater than 50 mm Hg
3. customPurification via silica gel chromatography

ORD record

ord-231a1c38e3b0437880357b4e0ed20694

Source dataset

uspto-grants-2012_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08309587B2