Subhash C. Jain

Insect repellents from vetiver oil: I. zizanal and epizizanal

Abstract On the basis of spectral data and partial syntheses, structure 1 and 2 are established for zizanal and epizizanal, two new insect-repelling aldehydes isolated from Javanese vetiver oil ( Vetiveria zizanoides ).

Antifeedant action ofZ-dihydromatricaria acid from soldier beetles (Chauliognathus spp.).

The acetylenic acid,Z-dihydromatricaria acid (DHMA), previously isolated from the defensive secretion ofChauliognathus lecontei, and now shown to occur also inC. pennsylvanicus, is a potent feeding deterrent to jumping spiders (Phidippus spp.). A simple bioassay withPhidippus is described, which is generally applicable to studies dealing with the isolation and evaluation of feeding deterrency of natural products from insects. By use of this assay,Phidippus were shown to be sensitive to as little as 1 μg DHMA, an amount equivalent to less than 2% of the DHMA content ofC. pennsylvanicus.

Stereoselective methodology for the synthesis of an antifungal allylamine: Terbinafine

The stereoselective synthesis of an antifungal drug, Terbinafine, bearing ( E)-tert-butylenyne structural element as the side chain is achieved by coupling N-methyl-1-napthalene methanamine with 1-bromo-6,6-dimethyl-2 E-hepten-4- yne in good yield. The new methodology avoids the use of toxic starting materials like acrolein and phosphorous penta- chloride that were used in earlier reports. The structure was confirmed by IR, NMR, MS, and elemental analysis.