Abstract: Dibenzo[d,g][1,3]dioxocin-6-carboxylic acids substituted by methyl or ethyl or a moiety --CH.sub.2 CH.sub.2 -- at the 12-position and optionally substituted at other positions, such as methyl 4'-chlorospiro(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carb oxylic acid, and their agriculturally acceptable esters, amides, and salts are useful for the control of undesirable vegetation. The 1,1-diarylcyclopropane intermediates required for the spirocyclopropane compounds can be prepared from appropriately substituted 1,1-diarylethene procursors by reaction with phenylthiomethyl lithium reagent.

Abstract: Dibenzo[d,g][1,3]dioxocin-6-carboxylic acids substituted by methyl or ethyl or a moiety --CH.sub.2 CH.sub.2 -- at the 12-position and optionally substituted at other positions, such as methyl 4'-chlorospiro(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carb oxylic acid, and their agriculturally acceptable esters, amides, and salts are useful for the control of undesirable vegetation. The 1,1-diarylcyclopropane intermediates required for the spirocyclopropane compounds can be prepared from appropriately substituted 1,1-diarylethene procursors by reaction with phenylthiomethyl lithium reagent.

Abstract: A method of preparing a compound of Formula XII ##STR1## wherein R.sub.1 and R.sub.2 together represent the fragment --Ch.sub.2 CH.sub.2 --;each R.sup.4 independently represents C.sub.1 -C.sub.4 alkyl optionally substituted with 1 to 2 C.sub.1 -C.sub.4 alkoxy groups; andX, X', Y, Y', Z, and Z' each, independently represent H, F, Cl, Br, I, CN, NO.sub.2, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, phenoxy, C.sub.1 -C.sub.4 alkylthio, phenylthio, or C.sub.1 -C.sub.4 dialkylamino, wherein each alkyl, alkoxy, and alkylthio group is optionally substituted with one or more compatible groups selected from C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 alkylthio, F, Cl, Br, CN, and phenyl and wherein each phenyl group is optionally substituted with up to 3 groups selected from F, Cl, Br, CN, CF.sub.3, C.sub.1 -C.sub.4 alkyl, and C.sub.1 -C.sub.4 alkoxy.

Abstract: 12H-Dibenzo[d,g][1,3]dioxocin-6-carboxylic acids having at least one selected substituent in the 1-, 3-, 4-, 8-, 9-, or 11-position, such as 4-chloro-12H-dibenzo[d,g][1,3]dioxocin-6-carboxylic acid, and their agriculturally acceptable salts, esters, and amides, are useful for the control of undesirable vegetation.

Abstract: Dibenzo[d,g][1,3]dioxocin-6-carboxylic acids substituted by methyl or ethyl or a moiety --CH.sub.2 CH.sub.2 -- at the 12-position and optionally substituted at other positions, such as methyl 4'-chlorospiro(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carb oxylic acid, and their agriculturally acceptable esters, amides, and salts are useful for the control of undesirable vegetation. The 1,1-diarylcyclopropane intermediates required for the spirocyclopropane compounds can be prepared from appropriately substituted 1,1-diarylethene procursors by reaction with phenylthiomethyl lithium reagent.