Enantio- and Regioselective Iridium-Catalyzed Allylic Esterification
摘要:
A highly enantioselective and regioselective Ir-catalyzed allylic esterification is described, in which branched allylic esters are synthesized directly. Carboxylates were used as nucleophiles and linear allylic phosphates as electrophiles. In some cases the allylic substitution reaction was found to be accompanied by a kinetic resolution process, which causes a change of the enantiomeric excess.
Synthesis of new macrocycles. Part 6. Pyridine-retronecate, a new synthetic alkaloid
作者:Siegfried E. Drewes、Andrew T. Pitchford
DOI:10.1039/p19810000408
日期:——
retronecic acid, results in the formation of a new semi-synthetic cyclic diester alkaloid, pyridine-retronecate. This product is an analogue of a pyrrolizidine alkaloid and retains those characteristics normally held responsible for the toxicity of this class of alkaloids. Biological tests carried out on mice injected with retrorsine and with the synthetic analogue suggest that the cytotoxic effects are