(1R,cis) 2,2-dimethyl-3-(cyclopentylidenemethyl)-cyclopropane-carboxylic acid → ethyl (1R,cis) 2,2-dimethyl-3-cyclopentylidenemethyl-cyclopropane-1-carboxylate

HRID 1995864Notes

Reaction equation

HRID 1995864 reaction equation
[CH:1](NC(=NC(C)C)OCC)(C)[CH3:2].[CH3:13][C:14]1([CH3:26])[C@@H:16]([CH:17]=[C:18]2[CH2:22][CH2:21][CH2:20][CH2:19]2)[C@H:15]1[C:23]([OH:25])=[O:24]>C(OCC)(=O)C>[CH3:13][C:14]1([CH3:26])[C@@H:16]([CH:17]=[C:18]2[CH2:22][CH2:21][CH2:20][CH2:19]2)[C@H:15]1[C:23]([O:25][CH2:1][CH3:2])=[O:24]

Participants

4

Reactant 2

HCID 11106237(1R,cis) 2,2-dimethyl-3-(cyclopentylidenemethyl)-cyclopropane-carboxylic acidHCID 20470583ethyl N,N'-diisopropylcarbamimidate

Product 1

HCID 53691429ethyl (1R,cis) 2,2-dimethyl-3-cyclopentylidenemethyl-cyclopropane-1-carboxylateYield 15.7%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Procedure

7.5 g of ethyl N,N'-diisopropyl-carbamimidate were added to a solution of 7.8 g of (1R,cis) 2,2-dimethyl-3-cyclopentylidenemethyl-cyclopropane-1-carboxylic acid in 20 ml of ethyl acetate and the mixture was refluxed for 2 hours and was filtered. The filtrate was evaporated to dryness and the 13 g of residue were chromatographed over silica gel. Elution with a 7-3 cyclohexane-ethyl acetate mixture and the fraction with a Rf=0.45 was evaporated to dryness under reduced pressure to obtain 1.4 g of ethyl (1R,cis) 2,2-dimethyl-3-cyclopentylidenemethyl-cyclopropane-1-carboxylate with a specific rotation of [α]D20 =+76°±2° (c=1% in ethanol).

Workup

  1. temperaturethe mixture was refluxed for 2 hours
  2. filtrationwas filtered
  3. customThe filtrate was evaporated to dryness
  4. customthe 13 g of residue were chromatographed over silica gel
  5. washElution with a 7-3 cyclohexane-ethyl acetate mixture
  6. customthe fraction with a Rf=0.45 was evaporated to dryness under reduced pressure

Sources & evidence

ORD record
ord-d4df50a28f8241b1aef59f63f0007000
Source dataset
uspto-grants-1983_09
Patent number
US04406829

Reaction notes

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