Tetrahydrofuran → Tert.-butyl(1R,cis)2,2-dimethyl-3-(carboxy ethynyl)cyclopropane-carboxylate

HRID 1762597Notes

Reaction equation

C([Li])CCC.[CH3:6][C:7]1([CH3:19])[CH:9]([CH:10]=[CH:11][C:12]([O:14]C)=[O:13])[CH:8]1[C:16]([OH:18])=[O:17].[CH3:20][C:21]1(C)[CH:23](C=C(Br)Br)[CH:22]1C([O-])=O.O1CCCC1>C1CCCCC1>[CH3:6][C:7]1([CH3:19])[C@@H:9]([C:10]#[C:11][C:12]([OH:14])=[O:13])[C@H:8]1[C:16]([O:18][C:21]([CH3:23])([CH3:22])[CH3:20])=[O:17]

Participants

Conditions

Temperature: -60 °C

Procedure

60 ml of a 20% solution of butyllithium in cyclohexane were added at -65° C. to a mixture of 26 g of tert.-butyl (1R, cis) 2,2-dimethyl-3-(2,2-dibromovinyl)-cyclopropane-carboxylate and 175 ml of anhydrous tetrahydrofuran and the mixture was stirred at -60° C. for one hour. A current of carbon dioxide was bubbled through the mixture for 90 minutes and the mixture was poured into an ice-water mixture containing N sodium hydroxide. The alkaline aqueous phase was acidified to a pH of 4 and was extracted with ether. The organic phase was dried and evaporated to dryness under reduced pressure. The residue was crystallized from petroleum ether (b.p.=60°-80° C. to obtain 8.3 g of tert.-butyl (1R,cis) 2,2-dimethyl-3-(3-hydroxy-3-oxo-1-propynyl)-cyclopropane-1-carboxylate melting at 144° C.

Workup

customA current of carbon dioxide was bubbled through the mixture for 90 minutes
additionthe mixture was poured into an ice-water mixture
additioncontaining N sodium hydroxide
extractionwas extracted with ether
customThe organic phase was dried
customevaporated to dryness under reduced pressure
customThe residue was crystallized from petroleum ether (b.p.=60°-80° C.

Sources & evidence

ORD record: ord-428f4a36d56a492180a5edfd7057f1f2
Source dataset: uspto-grants-1989_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04833163

Reaction notes

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