2- Heptanone, with acetic anhydride

Boron trifluoride-acetic acid, with acetic anhydride and 2-heptanone to give 3-n-butyl-2,4-pentanedione, 51, 90... 

A mixture of 28.6 g. (0.25 mole) of 2-heptanone (Note 1), 51.0 g. (0.50 mole) of acetic anhydride (Note 2), and 1.9 g. (0.01 mole) of p-toluenesulfonic acid monohydrate (Note 3) contained in a stoppered 500-ml. round-bottomed flask equipped with a magnetic stirrer is stirred at room temperature for 30 minutes. Then 55 g. (0.43 mole) of the solid 1 1 boron trifluoride-acetic acid complex (Note 4) is added some heat is evolved during this addition. The resulting amber-colored solution is stirred in the stoppered flask at room temperature for 16-20 hours (Note 5), and then a solution of 136 g. (1.00 mole) of sodium acetate trihydrate (Note 6) in 250 ml. of water is added. After the flask has been fitted with a reflux condenser, the reaction mixture is heated at reflux for 3 hours and then cooled,... 

The present procedures illustrate general methods for the use of preformed lithium enolates5 as reactants in the aldol condensation6 and for the quenching of alkali metal enolates in acetic anhydride to form enol acetates with the same structure and stereochemistry as the starting metal enolate.7 The aldol product, [Pg.55]

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