Diketene → N-(2-bornyl)-acetylacetamide

Participants

Reaction Conditions

Reaction Steps

16.8 g of diketene were added with stirring to a mixture of 30 g of 2-bornylamine and 200 ml of isopropyl ether and after stirring for 4 hours at 20° C., the mixture was evaporated to dryness under reduced pressure. The residue was chromatographed over silica gel and elution with a 9-1 methylene chloride-acetone mixture gave 39 g of N-(2-bornyl)-acetylacetamide. 30 g of the latter product and 1 g of p-toluene sulfonic acid were added to a mixture of 20 g of methyl orthoformate and 30 ml of methanol and the mixture stood at 20° C. for 16 hours. 2 ml of quinoline were added thereto and the mixture was evaporated to dryness under reduced pressure. The residue was added to toluene and the mixture was heated at 145° C. for 3 hours while distilling a toluene-methanol azeotrope. The mixture was evaporated to dryness under reduced pressure and the residue was chromatographed over silica gel. The product was eluted with an 8-2 methylene chloride-acetone mixture and was crystallized from isopropyl ether to obtain 19 g of N-(2'-bornyl)-3-methoxy-crotonamide melting at 149° C. The RMN spectra showed it was the E somer.

Provenance & Evidence