Diethyl Ether → rel-Methyl (1R,2S)-3-oxo-2-pentylcyclopentaneacetate

HRID 2377

Reaction equation

HRID 2377 reaction equation
[O:1]=[C:2]1[CH2:6][CH2:5][C@@H:4]([CH2:7][C:8]([OH:10])=[O:9])[C@H:3]1[CH2:11][CH2:12][CH2:13][CH2:14][CH3:15].[CH3:16]OS(OC)(=O)=O.CCOCC>CC(C)=O.O>[O:1]=[C:2]1[CH2:6][CH2:5][C@@H:4]([CH2:7][C:8]([O:10][CH3:16])=[O:9])[C@H:3]1[CH2:11][CH2:12][CH2:13][CH2:14][CH3:15]

Participants

6

Reactant 3

HCID 3283Diethyl EtherHCID 6497Dimethyl SulfateHCID 16061083(1S,2R)-3-oxo-2-pentyl-cyclopentaneacetic acid

Product 1

HCID 1738127rel-Methyl (1R,2S)-3-oxo-2-pentylcyclopentaneacetateYield 89.8%

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 962WaterSolvent

Procedure

To 104 mg (0.49 mmole) of (±)cis-3-oxo-2-pentyl-1-cyclopentaneacetic acid (93:7 cis/trans ratio) in 1 ml of (CH3)2CO there were added, first 56 μl of (CH3)2SO4 (74 ml, 0.59 mmole, 1.2 eq.) and then 81 mg (0.59 mmole, 1.2 eq.) of anhydrous solid K2 CO3. The resulting suspension was heated at r.t. during 4 h and taken in water and with ether. The ether phase was separated and the aqueous phase once more extracted with ether. The combined organic phases were washed with water, dried over MgSO4, filtered and concentrated. The residue was distilled in a bulb-to-bulb apparatus (oven t.: 180°/7 Pa) to provide 93 mg (0.44 mmole, yield 84%) of methyl (±)-cis-3-oxo-2-pentyl-1-cyclopentaneacetate (92/8 cis/trans ratio).

Workup

  1. customThe ether phase was separated
  2. extractionthe aqueous phase once more extracted with ether
  3. washThe combined organic phases were washed with water
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated
  7. distillationThe residue was distilled in a bulb-to-bulb apparatus (oven t.: 180°/7 Pa)

Sources & evidence

ORD record
ord-cb6326117e3045cb93e4c9a0471e9b58
Source dataset
uspto-grants-1998_03
Patent number
US05728866

Linked notes

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