Sodium hydride → HCID 23557313, compound

Participants

Reaction Steps

To a suspension of sodium hydride (0.11 g, 2.78 mmol) in THF (5 mL) at 0° C. was added a solution of di-tert-butyl malonate (0.53 mL, 0.5 g, 2.31 mmol) in THF (1.5 mL). The mixture was warmed to room temperature and stirred for 10 min. To the mixture was slowly added a solution of ethyl 6-bromohexanoate (0.42 mL, 0.52 g, 2.31 mmol) in THF (0.5 mL) and the mixture was stirred at 70° C. for 10 hours. After dilution of the mixture with ethyl acetate (10 mL), the solution was washed with water (20 mL) and brine (20 mL), dried over MgSO4 and evaporated. The residue was purified by chromatography on silica gel (80:20 petroleum ether 60-80° C.:ethyl acetate) to give the 2-tert-butoxycarbonyloctanedioate 1-tert-butyl ester 8-ethyl ester (14a) as a clear oil (0.61 g, 74%); Rf=0.33 (5:1 petroleum ether 60-80° C.:ethyl acetate); 1H NMR (300 MHz, CDCl3): δ 4.11 (2H, q, J=7.2 Hz, OCH2CH3), 3.37 (1H, t, J=5.7 Hz, COCH), 2.27 (2H, t, J=7.1 Hz, CH2CO), 1.87 (2H, br m, CHCH2CH2CH2CH2), 1.46 (2H, t, J=7.6 Hz, CHCH2), 1.37 (4H, br m, CHCH2CH2CH2), 1.22 (3H, t, J=7.2 Hz, OCH2CH3), 1.43 (18H, s, C(CH3)3); 13C NMR (75 MHz, CDCl3): δ 173.93 (CO), 173.93 (CO), 171.15 (CO), 61.14 (OCH2CH3), 51.66 (COCH), 33.89 (CH2CO), 29.44 (CH(CH3)3), 28.91 (CHCH2CH2CH2), 28.27 (CHCH2CH2), 26.83 (CHCH2CH2CH2CH2), 24.46 (CHCH2), 14.17 (OCH2CH3).

Provenance & Evidence