Further Studies on 1,4-Diphenyl-1,2,4-butanetrione Enol, Including Alkylation and Benzoylation

Abstract

The distribution functions possess maxima characteristics similar to those previously discussed for "r = 1" polymers. In fact, the same equations may be used for locating the xmax. value for * by replacing p with r!lp. Exact equations for Mw and Mz, corresponding to equations ( 13) and ( 14), are cumbersome; for all practical purposes it is permissible merely to replace p with r''lp in ( 13) and ( 14), respectively. It follows that here also the ratio of M": Mw: z approaches 1:2:3 for high molecular weights. Thus, sedimentation equilibrium measurements in the ultracentrifuge would not distinguish the two types of polymers.

The Configurations of the Alkoxy-1,2-Dibenzoyl-Ethylenes and Related Compounds

“…Phenoxydibenzoylethylenes-A and -B (cis and trans; I and II). Reaction between mesodibenzoylethylene dibromide (IV) and sodium phenoxide at 30-39°g ave the compound 8 In the cis forms this type of chelation would be most unlikely because it would require a sterically unfavorable arrangement of the two benzoyl groups in the all-planar arrangement required of effective conjugation. already known ( 5), here to be designated as isomer-A, in 35% yield.…”

Reduction of the Stereoisomeric 4-Enol Methyl Ethers of 1,4-Dimesityl-1,2,4-Butanetrione

“…Furthermore, there was isolated from the reaction mixture only a very small amount of the expected carbon-alkyl derivative (II) [to be described later (4)]. These results, therefore, are to be contrasted with the results of alkylation under similar conditions of the analogous diphenylbutanetrione silver enolate (3) where carbon alkylation is dominant.…”