(1S,3S)-2,2-Dimethyl-3-(2-methyl-1-propen-1-yl)cyclopropanecarbonyl chloride → (1R-trans)-2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropanecarbonyl chloride

HRID 2052168Notes

Reaction equation

[CH3:1][C:2]1([CH3:12])[C@@H:4]([CH:5]=[C:6]([CH3:8])[CH3:7])[C@@H:3]1[C:9]([Cl:11])=[O:10]>B(Cl)(Cl)Cl.C1(C)C=CC=CC=1>[CH3:1][C:2]1([CH3:12])[CH:4]([CH:5]=[C:6]([CH3:7])[CH3:8])[CH:3]1[C:9]([Cl:11])=[O:10]

Participants

Conditions

Temperature: 0 °C

Procedure

In a 200 ml flask, there were charged (-)-trans-2,2-dimethyl-3-isobutenylcyclopropane-1-carboxylic acid chloride (30.0 g) and toluene (70 g). Thereafter, boron trichloride (0.94 g) was added thereto at 0° C. with stirring under a nitrogen atmosphere, and the reaction was carried out for 10 minutes. After removal of the catalyst, the toluene was recovered by distillation, and the residue was distilled to obtain racemized 2,2-dimethyl-3-isobutenylcyclopropane-1-carboxylic acid chloride (27.0 g) having a boiling point of 72°-78° C./2 mmHg. The proportion of the optical isomers in this product was determined by gas chromatography. The result was as follows: (+)-trans, 46.8%; (-)-trans, 46.7%; (+)-cis, 3.3%; (-)-cis, 3.2%.

Workup

customAfter removal of the catalyst
distillationthe toluene was recovered by distillation
distillationthe residue was distilled

Sources & evidence

ORD record: ord-edd097a5300b4158a0f338a27e3c3699
Source dataset: uspto-grants-1980_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04182906

Reaction notes

Loading…