No abstract

Attempts t o synthesise a derivative of N-vinylaminoethanal either by oxidation of the corresponding alcohol or by hydrolysis of the corresponding dithioacetal were unsuccessful, but such derivatives were characterised b y H and 13C NMR spectroscopy of reactions between ethyl 2-aminoacetoacetate and an excess of ethyl acetoacetate, leading to diethyl 2,4-dimethylpyrrole-3,5-dicarboxylate.Porphobilinogen synthase (E.C. 4.2.1.24) catalyses the condensation of two molecules of 6-aminolaevulinic acid 1 (6-ALA) to form porphobilinogen 2, the precursor of chlorophylls, corrins and porphyrins. The zinc(l.1)-dependent human and bovine enzyme sequesters one molecule of compound 1 by forming an imine with the &-amino group of a lysine residue.' This enryme-bound species then reacts with the second molecule of 1 to afford, it is presumed, the intermediate 3 which cyclises and eventually yields the pyrrole 2 with release of the lysine residue (see Scheme l).2p4Puper 1/01277K

100ChemInform Abstract The amines (VI) and the ammonium chlorides (VII) respectively are prepared from the alcohols (I) by treatment with hydrazoic acid (II), triphenylphosphine (III), and the azodicarboxylate (IV) and subsequent hydrolysis of the intermediate aminophosphorane (V). The diamines (VIII) are obtained in an analogous manner.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.