Site-directed mutagenesis was used to identify key amino acid residues of the cholesterol oxidase from Streptomyces sp., which catalyzes the oxidation of cholesterol and the isomerization of 5-cholesten-3-one. Eight mutant enzymes were constructed and the following amino acid substitutions were identified: N318A, N318H, E356A, E356D, H441A, H441N, N480A and N480Q. Mutants N318A and N318H retain...

The conformation of the N-H bond in the title compound (23DCPCA), C(8)H(6)Cl(3)NO, is syn to both the 2- and 3-chloro substituents in the aromatic ring, similar to the 2-chloro substituent in 2-chloro-N-(2-chloro-phen-yl)acetamide (2CPCA), the 2- and 3-chloro substituents in N-(2,3-dichloro-phen-yl)acetamide (23DCPA) and in 2,2-dichloro-N-(2,3-dichloro-phen-yl)acetamide (23DCPDCA). The bond par...

The first Ni-catalysed alkene isomerization of allylamides for the synthesis of enamides was demonstrated. Various substituted N-allylamides were found to be suitable substrates for this isomerization. Isotopic labelling experiments showed that it is an intramolecular hydrogen transfer process.