Dicyclohexylcarbodiimide → tert.-butyl(1R,cis)2,2-dimethyl-3-[Z-2-(cyclobutoxycarbonyl)-ethenyl]cyclopropane-carboxylate
Reaction equation
C1(O)CCC1.[CH3:6][C:7]1([CH3:24])[CH:9](/[CH:10]=[CH:11]\[C:12]([O:14][CH:15]2[CH2:20][CH2:19][CH2:18]CC2)=[O:13])[CH:8]1[C:21]([OH:23])=[O:22].[CH3:25][C:26]1(C)[CH:28](/C=C\C(O)=O)[CH:27]1C([O-])=O.C1(N=C=NC2CCCCC2)CCCCC1>C(Cl)Cl.CN(C)C1C=CN=CC=1>[CH3:24][C:7]1([CH3:6])[C@@H:9](/[CH:10]=[CH:11]\[C:12]([O:14][CH:15]2[CH2:20][CH2:19][CH2:18]2)=[O:13])[C@H:8]1[C:21]([O:23][C:26]([CH3:28])([CH3:27])[CH3:25])=[O:22]Participants
7
Reactant 4
Product 1
Reagents, catalysts & solvents 2
Procedure
1.7 ml of cyclobutanol were added to a solution of 4 g of tert.-butyl (1R, cis) 2,2-dimethyl-3-[Z-2-carboxy-ethenyl]-cyclopropane-carboxylate in 20 ml of methylene chloride and 3.45 g of dicyclohexylcarbodiimide and a solution of 28 mg of 4-dimethylamino-pyridine in 20 ml of methylene chloride were added thereto at 0° to 5° C. with stirring. The mixture was stirred for 2 hours at 5° C. and 2 hours at room temperature and was then filtered. The filtrate was evaporated to dryness under reduced pressure and the residue was chromatographed over silica gel. Elution with a 9-1 n-hexane-isopropyl ether mixture yielded 2.3 g of tert.-butyl (1R,cis) 2,2-dimethyl-3-[Z-2-(cyclobutoxycarbonyl)-ethenyl]-cyclopropane-carboxylate.
Workup
- stirringThe mixture was stirred for 2 hours at 5° C. and 2 hours at room temperature
- filtrationwas then filtered
- customThe filtrate was evaporated to dryness under reduced pressure
- customthe residue was chromatographed over silica gel
- washElution with a 9-1 n-hexane-isopropyl ether mixture
Sources & evidence
- ORD record
- ord-cf8599a175474c7a81b7998b038b93e1
- Source dataset
- uspto-grants-1983_09
- Patent number
- US04402972
Reaction notes
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