Benzene → 2-methyl-4-oxo-3-(2propenyl)-2-cyclopenten-1-yl (1R,cis) 2,2-dimethyl-3-[(Z) 3-oxo-3-benzyloxy-1-propenyl]-cyclopropane-carboxylate

Participants

Reaction Steps

1 g of (1R,cis) 2,2-dimethyl-3-[(Z) 3-oxo-3-benzyloxy-1-propenyl]-cyclopropane-carboxylic acid chloride was added to a mixture of 450 mg of (S) 3-(2-propenyl)-1-hydroxy-2-methyl-4-oxo-cyclopent-2-en-1-yl, 20 ml of benzene and 0.6 ml of pyridine and the mixture was stirred for 6 hours and was then poured into a mixture of iced water and N hydrochloric acid. The mixture was extracted with benzene and the combined benzene phases was washed with water, dried and evaporated to dryness. The 1.5 g of residue was chromatographed over silica gel and was eluted with an 8-2 cyclohexane-ethyl acetate mixture to obtain (1S) 2-methyl-4-oxo-3-(2propenyl)-2-cyclopenten-1-yl (1R,cis) 2,2-dimethyl-3-[(Z) 3-oxo-3-benzyloxy-1-propenyl]-cyclopropane-carboxylate having a specific rotation of [α]D20 =+37°±2.5 (c=0.5% in benzene).

Provenance & Evidence