Cyclopentanone → 2-Cyclohexyl-3-oxo-3-(2-oxo-cyclopentyl)-propionic acid ethyl ester

HRID 889370Notes

Reaction equation

[Li+].CC([N-]C(C)C)C.[C:9]1(=[O:14])[CH2:13][CH2:12][CH2:11][CH2:10]1.[CH2:15]([O:17][C:18](=[O:37])[CH:19]([CH:31]1[CH2:36][CH2:35][CH2:34][CH2:33][CH2:32]1)[C:20](N1C2C=CC=CC=2N=N1)=[O:21])[CH3:16]>C1COCC1>[CH2:15]([O:17][C:18](=[O:37])[CH:19]([CH:31]1[CH2:36][CH2:35][CH2:34][CH2:33][CH2:32]1)[C:20](=[O:21])[CH:10]1[CH2:11][CH2:12][CH2:13][C:9]1=[O:14])[CH3:16]

Participants

Conditions

Temperature: -78 °C

Procedure

To a −78° C. cold solution of LDA (2 M solution in heptane/ethylbenzene/THF, 15.7 ml, 31 mmol) in THF (96 ml) under an argon atmosphere was added a solution of cyclopentanone (2.78 ml, 31 mmol; CAS Reg. No. 120-92-3) in THF (72 ml) within 25 min. The mixture was stirred for 2 h at −78° C. A solution of 3-benzotriazol-1-yl-2-cyclohexyl-3-oxo-propionic acid ethyl ester (9 g, 29 mmol) in THF (63 ml) was added and the solution was stirred at ambient temperature for 14 h. Ice water was added, the mixture was poured onto ice water/brine 1/1 and extracted two times with TBME. The combined extracts were washed with ice water/brine 1/1 and dried over Na2SO4. After filtration the solvent was removed under reduced pressure to give the title compound (8.8 g; quant.) which was used in the next step without further purification.

Workup

stirringthe solution was stirred at ambient temperature for 14 h
extractionextracted two times with TBME
washThe combined extracts were washed with ice water/brine 1/1
dry with materialdried over Na2SO4
filtrationAfter filtration the solvent
customwas removed under reduced pressure

Sources & evidence

ORD record: ord-473ae73027584a7cb4039ff0af716237
Source dataset: uspto-grants-2012_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08252826B2

Reaction notes

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