Structure of (−)-Neodysidenin from Dysideaherbacea. Implications for Biosynthesis of 5,5,5-Trichloroleucine Peptides
摘要:
[GRAPHICS]Neodysidenin was isolated from the marine sponge Dysidea herbacea (Keller 1889) collected on the Great Barrier Reef. The complete configuration was obtained from a combination of methods, including capillary electrophoresis of Marfey's derivatives. Neodysidenin belongs to the L-series of trichloroleucine peptides, and the configuration of the N-methyl thiazolyl alanine residue (13R) is opposite to that of dysidenin.
Formation of a reasonably stabilized trichloromethyl anion by the reaction of chloroform with electrogenerated base, and its 1,4-addition to α,β-unsaturated carbonyl compounds
A reasonably stabilized trichloromethylanion (TCMA) was formed by the reaction of chloroform with an electrogenerated base prepared by the electroreduction of 2-pyrrolidone, and the addition of this TCMA to α,β-unsaturated esters gave the corresponding β-trichloromethyl esters in good yields.