An expedient synthesis of 3-acyltetramic acids of the melophlin family from α-aminoesters and immobilized Ph3PCCO
作者:Rainer Schobert、Carsten Jagusch
DOI:10.1016/j.tet.2005.01.036
日期:2005.2
The naturally occurring 3-acyltetramicacids (3-acylpyrrolidine-2,4-diones) melophlin A, B, C and G were prepared in few steps from α-aminoesters or their hydrochlorides by cyclization with Ph3PCCO under mild conditions. The employment of immobilized, polystyrene-bound ylide greatly simplifies the removal of by-product Ph3PO and of other impurities. Various 3-acylation methods were assessed.
Two novel tetramicacids named melophlins A (1) and B (2) were isolated from the marinesponge Melophlus sarassinorum, and the absolute stereostructures were elucidated on the basis of chemical and physicochemical evidence. Melophrins A (1) and B (2) induced reversion of the tumorous phenotype of ras-transformed NIH3T3 cells to normal at the concentration of 5 μg mL−1.