SYNTHESIS AND HERBICIDAL ACTIVITY OF HYDANTOCIDIN ANALOGS - MODIFICATION OF THE CARBONYL GROUPS IN SPIROHYDANTOIN

Syntheses of two carbonyl derivatives of hydantocidin 1, a potent, nat urally occurring herbicide, and their herbicidal activity are describe d. Spiroimidazolidinone 2, the descarbonyl compound at C9, was prepare d by employing reductive demethylsulfurization with tri-n-butyltin hyd ride as the key step. Another derivative, spiroimidazolinone 10, was o btained from alpha-azidoamide 8 and benzyl isocyanate via the aza-Witt ig reaction. 2 had lost almost all herbicidal activity, whereas 10 ret ained herbicidal activity against such dicotyledonous weeds as ragweed and cocklebur, but lost activity against monocotyledonous weeds. Thes e results imply the possibility that proper modification of the carbon yl group at C7 of the parent compound would afford hydantocidin analog ues possessing crop selectivity.