Citric Acid → HCID 54345618, compound

HRID 636011Notes

Reaction equation

C(NC(C)C)(C)C.C([Li])CCC.[OH:13][C@H:14]([CH2:20][CH2:21][CH3:22])[CH2:15][C:16]([O:18][CH3:19])=[O:17].[CH2:23](Br)[C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1.C(O)(=O)CC(CC(O)=O)(C(O)=O)O>C1COCC1.C1COCC1.CN(P(N(C)C)(N(C)C)=O)C>[CH2:23]([C@H:15]([C@H:14]([OH:13])[CH2:20][CH2:21][CH3:22])[C:16]([O:18][CH3:19])=[O:17])[C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1

Participants

Conditions

Temperature: -78 °C

Procedure

Diisopropylamine (8.61 mL, 65.7 mmol) is dissolved in 40 mL of anhydrous THF and chilled to 0° C. n-Butyllithium (30.1 mL of a 2.0M solution in hexanes, 60.2 mmol) is added dropwise over 10 min and the resulting pale yellow solution cooled to −78° C. A 15-mL THF solution of methyl (3R)-3-hydroxyhexanoate (4.00 g, 27.4 mmol) is added over 10 min and stirred for 30 min. Benzyl bromide (3.60 mL, 30.1 mmol) is dissolved in 12 mL of a 1:1 THF/HMPA solution and added at −78° C. dropwise. The resulting solution is allowed to warm slowly to 0° C. over 3 h. Aqueous 5% citric acid solution (250 mL) is added and the organics are extracted with two 250-mL portions of ether. The combined organics are washed with saturated aqueous sodium chloride. Drying over sodium sulfate and concentration is followed by which is chromatography on silica gel (elution with 25% EtOAc-hexanes) giving methyl (2R,3R)-2-benzyl-3-hydroxyhexanoate as an oil (3.03 g, 64% yield).

Workup

additionis added dropwise over 10 min
additionadded at −78° C. dropwise
temperatureto warm slowly to 0° C. over 3 h
extractionthe organics are extracted with two 250-mL portions of ether
washThe combined organics are washed with saturated aqueous sodium chloride
dry with materialDrying over sodium sulfate and concentration

Sources & evidence

ORD record: ord-a123a8f22f704d419d14b2bd68a4dd47
Source dataset: uspto-grants-2001_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06191150B1

Reaction notes

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