Isopropylmalonic acid

This also follows from the results obtained by Koehl [98]. In the oxidation of monoesters of methylpropylmalonic and methyl-isopropylmalonic acids Eberson [93] obtained a mixture of the diastereoisomers of Q, Q -dimethyl-Q, o -dipropylsuccinic and dimethyl-Q, Q -diisopropylsuccinid acids. During electrolytic oxidation of meso- and racemic 2,3-diphenylsuccinic acids in a mixture of pyridine and water (9 1) Corey and Casanova [94] obtained only trans-stilbene, which is also formed in the oxidation of these acids by lead tetraacetate. It is pointed out that these results exclude the possibility of cis-elimination. In the case of anodic oxidation of butylboric acid Humphrey and Williams [96] found that a mixture of 1-butene, cis-2-butene, and trans-2-butene in the proportions 3.3 1 1 was formed at a platinum electrode in aqueous alkaline solutions at low current densities. 

The crude amino-acid (75) when treated with dicyclohexylcarbodi-imide gave a y9-lactam identical with acetylpachystermine B (73c). Reduction of the latter with lithium aluminium hydride gave pachystermine B (73b), which in turn was oxidized to pachystermine A (73a). On the other hand, the product (72b), an acyl-migration product of epipachysandrine A (72a), when treated with the acyl chloride of ethyl isopropylmalonate gave a condensation product which, when reduced with lithium aluminium hydride, afforded a mixture of 3 -epimeric diols (76). 

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