tert-butyl N-[(2S)-4-methyl-1-oxopentan-2-yl]carbamate → tert-butyl ((3S)-2-hydroxy-5-methylhexan-3-yl)carbamate
Reaction equation
[CH3:1][CH:2]([CH3:15])[CH2:3][C@H:4]([NH:7][C:8](=[O:14])[O:9][C:10]([CH3:13])([CH3:12])[CH3:11])[CH:5]=[O:6].[CH3:16][Mg]Br>C(OCC)C>[OH:6][CH:5]([C@@H:4]([NH:7][C:8](=[O:14])[O:9][C:10]([CH3:13])([CH3:12])[CH3:11])[CH2:3][CH:2]([CH3:15])[CH3:1])[CH3:16]Participants
Conditions
- Temperature
- 0 °C
Procedure
A solution of (S)-tert-butyl (4-methyl-1-oxopentan-2-yl)carbamate (1.3 g, 6.04 mmol) in diethyl ether (50 mL) was cooled to −78° C. and treated with methyl magnesium bromide (1.4 M in diethyl ether) (8.63 mL, 12.08 mmol). The slurry was stirred at 0° C. for 1 h and then stirred for an additional hour at RT. The reaction mixture was quenched with NH4Cl. The reaction mixture was extracted with diethyl ether (3×100 mL). The combined organic layers were washed with brine, dried over MgSO4, and concentrated to afford the product, tert-butyl ((3S)-2-hydroxy-5-methylhexan-3-yl)carbamate (1 g, 4.32 mmol, 72% crude yield) as colorless oil. The material was carried on without further purification. 1H NMR (300 MHz, DMSO-d6): δ 0.78-0.93 (m, 6H), 0.98 (d, 3H), 1.11-1.41 (m, 2H), 1.42 (s, 9H), 1.45-1.64 (m, 1H), 3.30-3.63 (m, 2H), 4.37 (d, 1H), 6.19 (d, 1H).
Workup
- stirringstirred for an additional hour at RT
- customThe reaction mixture was quenched with NH4Cl
- extractionThe reaction mixture was extracted with diethyl ether (3×100 mL)
- washThe combined organic layers were washed with brine
- dry with materialdried over MgSO4
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-271a96cb574e473ebed497413a206fee
- Source dataset
- uspto-grants-2014_12
- Patent number
- US08901305B2
Reaction notes
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