Dicyclohexylcarbodiimide → (RS)1-(6-phenoxy-2-pyridyl)-ethyl(1R,cis,Z)2,2-dimethyl-3-[3-oxo-3-tert.-butoxy-1-propenyl]-cyclopropane-carboxylate

Participants

Reaction Conditions

Reaction Steps

A solution of 55.7 g of dicyclohexylcarbodiimide, 2.6 g of 4-dimethylamino-pyridine and 450 ml of methylene chloride were added over 25 minutes at 0° C. to a mixture of 65 g of (1R,cis,Z) 2,2-dimethyl-3-[3-oxo-3-tert.-butoxy-1-propenyl]-cyclopropane-carboxylic acid, 70 g of (RS) 1-(6-phenoxy-2-pyridyl)-ethanol and 650 ml of methylene chloride and the mixture was stirred at 20° C. for 4 hours and was vacuum filtered. The filtrate was evaporated to dryness and the residue was chromatographed over silica gel. Elution with an 100-4 n-hexane-ethyl acetate mixture yielded 101 g of (RS) 1-(6-phenoxy-2-pyridyl)-ethyl (1R,cis,Z) 2,2-dimethyl-3-[3-oxo-3-tert.-butoxy-1-propenyl]-cyclopropane-carboxylate with a specific rotation of [αD20 =+64° (c=1% in toluene).

Provenance & Evidence