Formation and Reactions of 1-Phenyl-2-propanone Dianion and Related Systems with Electrophilic Reagents

Article abstract of DOI:10.1021/jo00166a004

1-Phenyl-2-propanone, 1,1-diphenyl-2-propanone, and 1-(4-methoxyphenyl)-2-propanone were converted to their dicarbanions 3, 4, and 31, respectively, and their reactions with a number of electrophilic reagents were examined.All three dianions gave a mixture of C-1 and C-3 alkylation products when treated with alkyl halides of higher reactivity, while only C-1 alkylations occurred when alkyl halides of lower reactivity were used.It was also found that the 1,1-diphenyl-2-propanone and the 1-(4-methoxyphenyl)-2-propanone dianions 4 and 31 gave a higher ratio of C-1/C-3 alkylation products than the 1-phenyl-2-propanone dianion 3.When dianion 3 was reacted with p-anisaldehyde and a number of protonating agents, electrophilic attack occurred exclusively at the C-3 position.The trends observed are analyzed, and mechanisms are proposed to account for the results obtained.