The preparation of synthetic analogues of strigol

A range of analogues of the natural germination stimulant, strigol, for parasitic weeds of the genera Striga and Orobanche, has been prepared. Most of the products contain an α-formyl-γ-lactone (or α-formyl-γ-lactam) grouping attached through an enol-ether linkage to the 5-position of a but-2-enolide. Some have shown sufficiently high activities as to warrant large-scale field trials.