VILLIRAMULIN-A AND VILLIRAMULIN-B - NEW PHENOL DERIVATIVES FROM PIPER-VILLIRAMULUM

Two new phenol derivatives, villiramulin A (1) and B (2), have been is olated from the Panamanian plant Piper villiramulum and assigned struc tures on the basis of a variety of spectroscopic data. After a model s tudy wherein the (+)- and (-)-O-methylmandelate esters of 2-heptanol w ere shown to present significantly different H-1 NMR spectra, villiram ulin A was esterified with both of these acids. On the basis of the H- 1 NMR data of the resulting esters, the S stereochemistry was assigned to the natural product. Finally, villiramulin B was shown to be signi ficantly active in a bioassay that measures repellency to a captive co lony of leafcutter ants.