Synthesis of 1-diazo-3-methoxy-3-phenyl-2-propanone and reaction with boron trifluoride etherate

It has been found that the normal reaction of diazoketones with an acid to form substituted methyl ketones is often subverted by cyclization to form closed chain cyclic ketones. Some work has been done with aromatic diazoketones but very little has been done with the aliphatic diazoketones. The object of this research was to bring about ring closure of a four membered ring from an aliphatic diazoketone. It was decided to put a phenyl group on the aliphatic chain in order to obtain crystalline derivatives. Specifically, the object of this work was to bring about the cyclization of 1-diazo-3-methoxy-3-phenyl-2-propane. The diazoketone must be synthesized from the respective acid, D, L – phenyl-2-methoxy-acetic acid, by a series of steps which involve: (1) the conversion of the acid to the acid chloride upon treatment with thionyl chloride, (2) the conversion of the acid chloride to the diazoketone upon treatment with diazo methane. Diazomethane will be written: CH2N2. It is actually a resonance hybrid of the two forms