Tetrahedron Reports on Organic Chemistry, Volume 4 contains 10 tetrahedron reports on organic chemistry with report numbers 31-40. Some reports focus on organopalladium intermediates in organic synthesis; the synthesis of insect sex pheromones; and boraheterocycles via cyclic hydroboration. Other tetrahedron reports center on synthesis of polyketide-type aromatic natural products by biogenetically modeled routes; Ei reaction of sulphilimines and related compounds; strategies in optical resolutions; and the diradical mechanism for 1,3-dipolar cycloadditions and related thermal pericyclic reactions.