Dimethyl dicarbonate → rel-Methyl (1R,2S)-3-oxo-2-pentylcyclopentaneacetate
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].[C:16](OC(OC)=O)(OC)=O>CO>[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
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
104 Mg (0.49 mmole) of (+)-cis-3-oxo-2-pentyl-1-cyclopentaneacetic acid (97:3 cis/trans ratio) in 0.5 ml of methanol were treated with 76 μl of dimethyl dicarbonate [CH3O(CO)O(CO)OCH3, origin: Bayer; 96 mg, 0.72 mmole, 1.5 eq.]. The resulting solution was heated to 45° during 16 h and then evaporated under vacuum. After distillation of the residue in a bulb-to-bulb apparatus (oven t. 150°/10 Pa), there were obtained 100 mg (0.44 mmole, yield 90%) of pure methyl (±)cis-3-oxo-2-pentyl-1-cyclopentaneacetate (97:3 cis/trans ratio).