Diethyl 2-Isopentyl-2-methylmalonate → 2-Formyl-2,5-dimethyl-hexanoic acid ethyl ester

Temperature

25 °C

Diisobutylaluminum hydride (97.5 mL of a 1.0 M solution in toluene, 97.5 mmol) was added over 10 min to a solution of rac-2-methyl-2-(3-methyl-butyl)-malonic acid diethyl ester (11.91 g, 48.7 mmol) in dichloromethane (100 mL) at −78° C. The reaction mixture was stirred at that temperature for 4 h, and then was quenched with saturated aqueous ammonium chloride (100 mL). The cold bath was removed, 1.0 M aqueous hydrochloric acid solution (300 mL) and DL-tartaric acid (12 g) were added sequentially, and the mixture was allowed to warm to 25° C. over 2 h with vigorous stirring. The biphasic mixture was then partitioned between 1.0 M aqueous hydrochloric acid solution (150 mL) and dichloromethane (350 mL). The organic layer was dried over sodium sulfate and was concentrated in vacuo to afford the crude product, rac-2-formyl-2,5-dimethyl-hexanoic acid ethyl ester (8.80 g, 44 mmol, 90%).

1. customwas quenched with saturated aqueous ammonium chloride (100 mL)
2. customThe cold bath was removed
3. addition1.0 M aqueous hydrochloric acid solution (300 mL) and DL-tartaric acid (12 g) were added sequentially
4. customThe biphasic mixture was then partitioned between 1.0 M aqueous hydrochloric acid solution (150 mL) and dichloromethane (350 mL)
5. dry with materialThe organic layer was dried over sodium sulfate
6. concentrationwas concentrated in vacuo

ORD record

ord-9623b0bf6a7c4b49ad8e1c66f29902c9

Source dataset

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08097613B2