Methyl Ethyl Ketone → 4-(Bicyclo[2.2.1]hept-5-en-2-yl)-3-methylbut-3-en-2-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 80 ml. of 2-butanone (1.1 moles), 61.1 grams (0.5 moles) of 5-norbornene-2-carboxaldehyde, and 250 ml. of water containing 6 ml. of 40% sodium hydroxide solution was stirred rapidly at 50°C. for 2 hours when most of the aldehyde had been consumed (as determined by infrared analysis) and an aldol had formed. Stirring was continued and the temperature was slowly raised to 70°C. and kept there for 30 minutes causing dehydration of 75% of the aldol. A small amount of toluene sulfonic acid was added which catalyzed the dehydration of the remaining aldol. 90.8 grams of crude material which was a viscous liquid was distilled through a short Vigreux-column to give 4-(5-norbornenyl)-3-methyl-but-3-en-2-one which had a boiling point of 121°-122°C. at 10 mm., nD 25 = 1.5156.

Provenance & Evidence