Sec.-Butyl magnesium bromide

An excellent method for converting an acid chloride to a ketone employs transition metal catalysts such as ferric chloride in conjunction with low reaction temperatures. Reaction of butylmagnesium bromide with octanoyl chloride at -60°C gave a mixture of 13% of 80, 4% of 81 (from the secondary reaction of butyl-magnesium bromide and 80), and 60% of 82. when a catalytic amount (2 mol %) of ferric chloride (FeCls) was added, however, a 76% yield of ketone 80 was obtained, along with 3% of the over alkylation product, 81.94 If the intermediate ketone is unreactive to nucleophilic substitution due steric hindrance or peculiar electronic factors (diisopropyl ketone and phenyl-rerr-butyl ketone are both sterically hindered) the ketone can usually be isolated (sec. 8.4.G for problems with hindered ketones). In many instances, however, even dry ice temperatures and reverse addition techniques give poor yields of the ketone.95... 

The solution from 12 grams of magnesium, 75 grams of sec-butyl bromide in 500 e.c. ether, is treated with 45 grams of mercuric chloride, and the mixture then boiled for eight hours on the water-bath and decomposed in the usual way. Yield 66 per cent. ... 

---