4(Z-3-chloroallyl)benzyl alcohol → 4(Z-3-chloroallyl)benzyl(1R)cis-3(2,2-dibromovinyl)-2,2-dimethylcyclopropane carboxylate
Reaction equation
[Br:1][C:2]([Br:12])=[CH:3][C@H:4]1[C@@H:6]([C:7]([O-:9])=[O:8])[C:5]1([CH3:11])[CH3:10].[Cl:13]/[CH:14]=[CH:15]\[CH2:16][C:17]1[CH:24]=[CH:23][C:20]([CH2:21]O)=[CH:19][CH:18]=1>C(Cl)Cl.CN(C)C1C=CN=CC=1>[Br:1][C:2]([Br:12])=[CH:3][C@H:4]1[C@@H:6]([C:7]([O:9][CH2:21][C:20]2[CH:23]=[CH:24][C:17]([CH2:16]/[CH:15]=[CH:14]\[Cl:13])=[CH:18][CH:19]=2)=[O:8])[C:5]1([CH3:10])[CH3:11]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 2
Procedure
To a solution of (1R)cis 3(2,2-dibromovinyl)-2,2-dimethylcyclopropane carboxylate (0.11 g) in CH2Cl2 (3 ml) cooled to 0° is added successively 4(Z-3-chloroallyl)benzyl alcohol (0.070 g) in CH2Cl2 (2 ml), N,N1 dicyclohexylcarbodiimide (0.076 g) in CH2Cl2 (2 ml), and 4-dimethylamino pyridine (0.010 g). This mixture is stirred for 30 minutes at 0°, then for 16 hours at 20°. The resulting precipitate is filtered off, the filtrate evaporated under reduced pressure and the residue chromatographed on florisil. The fraction eluted by 7% diethyl ether in petroleum ether bp 60°-80° C. ether in petrol is evaporated to a residue of 4(-3-chloroallyl)benzyl (1R)cis-3(2,2-dibromovinyl)-2,2-dimethylcyclopropane carboxylate (0.15 g) 91% nD20 1.5684.
Workup
- waitfor 16 hours at 20°
- filtrationThe resulting precipitate is filtered off
- customthe filtrate evaporated under reduced pressure
- customthe residue chromatographed on florisil
- washThe fraction eluted by 7% diethyl ether in petroleum ether bp 60°-80° C. ether in petrol
- customis evaporated to a residue of 4(-3-chloroallyl)benzyl (1R)cis-3(2,2-dibromovinyl)-2,2-dimethylcyclopropane carboxylate (0.15 g) 91% nD20 1.5684
Sources & evidence
- ORD record
- ord-9cfb6eed221243ff8e2a1a2382980a4d
- Source dataset
- uspto-grants-1987_05
- Patent number
- US04668701
Reaction notes
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