Reaktion #310940

Reaktionsgleichung

benzene

2,2-dimethyl-3-cyclopentylidenemethyl-cyclopropane-1-carboxylic acid chloride

water

benzene

pyridine

→

( 1S )

2-methyl-3-allyl-4-methylene-cyclopent-2-ene-1-yl (1R,cis) 2,2-dimethyl-3-cyclopentylidenemethyl-cyclopropane-1-carboxylate

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe mixture was stirred for 10 minutes
2. 2
   Extraktionwas then extracted with methylene chloride
3. 3
   WaschenThe combined organic phases were washed with water
4. 4
   Trocknendried over magnesium sulfate
5. 5
   Filtrationfiltered
6. 6
   SonstigeThe filtrate was evaporated to dryness under reduced pressure
7. 7
   Sonstigethe residue was chromatographed over silica gel
8. 8
   WaschenElution with a 95-5 cyclohexane-ethyl acetate mixture
9. 9
   workup.ADDITIONcontaining 1‰ triethylamine

Vorschrift

30 ml of a benzene solution of (1R, cis) 2,2-dimethyl-3-cyclopentylidenemethyl-cyclopropane-1-carboxylic acid chloride prepared from 7 g of the corresponding acid were added at 20° C. over 15 minutes to a mixture of 4 g of 1S-hydroxy-2-methyl-3-allyl-4-methylene-cyclopent-2-ene, 10 ml of benzene and 5 ml of pyridine and the mixture was stirred at 20° C. for 20 hours and was then poured into 30 ml of water. The mixture was stirred for 10 minutes and was then extracted with methylene chloride. The combined organic phases were washed with water, dried over magnesium sulfate and filtered. The filtrate was evaporated to dryness under reduced pressure and the residue was chromatographed over silica gel. Elution with a 95-5 cyclohexane-ethyl acetate mixture containing 1‰ triethylamine yielded 4.1 g of (1S) 2-methyl-3-allyl-4-methylene-cyclopent-2-ene-1-yl (1R, cis) 2,2-dimethyl-3-cyclopentylidenemethyl-cyclopropane-1-carboxylate.

Quelle