Phenylhydrazine → Ethyl chrysanthemate
Reaction equation
C(=N[C@H](C)C(C1C=CC=CC=1)(C1C=CC=CC=1)O)C1C(=CC=CC=1)O.[CH3:26][C:27](=[CH:29][CH:30]=[C:31]([CH3:33])[CH3:32])[CH3:28].C1(NN)C=CC=CC=1.[N+](=[CH:44][C:45]([O:47][CH2:48][CH3:49])=[O:46])=[N-]>O.C([O-])(=O)C.[Cu+2].C([O-])(=O)C>[CH3:49][CH2:48][O:47][C:45]([CH:44]1[C:31]([CH3:33])([CH3:32])[CH:30]1[CH:29]=[C:27]([CH3:28])[CH3:26])=[O:46]Participants
Conditions
- Temperature
- 25 °C
Procedure
19.64 mg (0.05 mmol) of copper complex prepared from 9.98 mg (0.05 mmol) of copper acetate monohydrate, and 18.23 mg of (R)-N-salicylidene-2-amino-1,1-diphenylpropanol, and 6.0 g(55 mmol) of 2,5dimethyl-2,4-hexadiene were charged in a 50 ml Schienk's tube wherein the atmosphere was replaced with nitrogen, and then 5.4 mg of phenylhydrazine. 1.14 g (10 mmol) of ethyl diazoacetate was added dropwise at 50° C. over 2 hours and further stirred for 1 hour at 25° C. The amount of chrysanthemic acidethyl ester formed was determined by gas chromatography. As a result, it was 1.52 g and the yield was 77.7% based on t-butyl diazoacetate and, furthermore, the trans/cis ratio was 61/39. After 2,5-dimethyl-2,4-hexadiene (boiling point: 51° C./30 mmHg) was distilled off from the reaction mixture. Then, 10 ml of an aqueous 1N sodium hydroxide solution and 5 ml of ethanol were added to 1 g of the concentrate and alkali hydrolysis was performed by stirring at 100° C. for 1 hour. The obtained chrysanthemic acid was reacted with I-menthol, and the resulted diastereomer was analyzed by gas chromatography, which showed the optical purity of (+)-trans isomer was 69% e.e. and that of (+)-cis isomer was 68% e.e.
Workup
- additionwere charged in a 50 ml Schienk's tube wherein the atmosphere
Sources & evidence
- ORD record
- ord-0045a747f1764cee8e99a98c9756a913
- Source dataset
- uspto-grants-2001_07
- Patent number
- US06268525B1
Reaction notes
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