SELECTIVE OXABICYCLOALKANES

Abstract: This invention relates to compounds, agriculturally suitable compositions thereof, and a method for controlling the growth of undesired vegetation in paddy rice crops by applying an effective amount of an oxabicycloalkane herbicidal compound to the locus of paddy rice.

Description: SELECTIVE PXAPICYCLOALKANES Related Applications This application is a continuation-in-part of copending application U.S. Serial Mo. 07/096442 filed September 15, 1987. Background of the Invention This invention relates to compounds, agricul¬ turally suitable compositions thereof, and a method for controlling the growth of undesired vegetation in paddy rice with an oxabicycloalkane herbicide. U.S. 4,670,041 and U.S. 4,486,219 disclose oxabicycloalkanes and their use for controlling plant growth. Summary of the Invention This invention comprises a method for control¬ ling the growth of undesired vegetation in a paddy rice crop by applying to the locus of the paddy rice crop an effective amount of a compound of Formula I wherein χ is CH 3 or CH 2 CH 3 ; R 2 and R 3 are independently CH 3 or CH 2 CH 3 or R 2 and R 3 may be taken together as -(CH 2 ) n - where n is 4 or 5; R 4 is CH 3 or CH 2 CH 3 ; 5 and R 6 are independently CH 3 or CH CH ; R 7 is CH 3 or CH 2 CH 3 ; R 8 is CH 3 , CH 2 CH 3 or CH(CH 3 ) 2 ; 0=1 0=1 0=2. 0= X and Y are independently H, F, Cl or CH 3 ; R 9 is F, Cl, Br, CH 3 or CH 2 CH 3 ; and R 10 is H, F, Cl or CH 3 ; provided that when J is J-3, then Q is Q-3 or Q-4. Preferred for reasons of more efficient weed control and/or. better crop tolerance are: 1. The method wherein R± is CH 3 ; R 2 and R 3 are CH 2 CH 3 or R 2 and R3 are taken together as -(CH 2 ) n - where n is 4 or 5; R 4 is CH 3 ; R 5 and Rg are CH 3 ; R 7 is CH 3 ; and 5 R 8 is CH(CH 3 ) 2 . 2. The method wherein the cro -is transplanted japonica rice. 3. The method wherein the crop is transplanted 0 indica rice. 4. The method wherein among the weeds controlled is barnyardgrass. Specifically preferred for reasons of most efficient weed control and/or better crop tolerance is T5 the method wherein the compound of Formula I is selected from the group consisting of: endo-4-[(2-fluorophenyl)methoxy]-5,7,7-tri¬ methy1-6-oxabicyclo[3.2.1]octane; 6-ejij3__Q-benzyloxy-l-methyl-3,3-tetramethylene- 20 2-oxabicyclo[2.2.2]octane; 6-endo-benzyloxy-l-meth l-3,3-pentamethylene- 2-oxabicyclo[2.2.2]octane; 6-endo-[(2-fluorophenyl)methoxy]-3,3-penta- methylene-2-oxabicyclo[2.2.2]octane; yε. 1-methy1-3,3-diethyl-6-e_nclo_-[(2-fluoro- phenyl)methoxy]-2-oxabicyclo[2.2.2]octane; ejto_-2-[(2-bromo-3-thienyl)methoxy]-1-meth 1-4- (l-methylethyl)-7-oxabicyclot2.2.1]heptane; £2 _-2-[(2-ethyl-3-thienyl)methoxy]-1-methy1-4- 2 Q (1-methylethyl)-7-oxabicyclo[2.2.1]heptane; and exo-2-f(2-methy1-3-thienyl)methoxy]-1-methy1-4- (l-methylethyl)-7-oxabicyclo[2.2.1]heptane. , t This invention also comprises compounds of Formula I wherein Q is Q-3 or Q-4 and agriculturally suitable compositions containing them. Preferred compounds of the invention for reasons •of more efficient weed control and/or better crop tolerance are: 1. The compounds of Formula I wherein R j is CH 3 ; 0 R 2 and R 3 are CH 2 CH 3 or R 2 ' and R 3 are taken together as -(CH 2 ) n where n is 4 or 5; R 4 is CH 3 ; R 5 and R 6 are CH 3 ; R 7 is CH 3 ; and lδ R 8 is CH(CH 3 ) 2 . 2. The compounds of Preferred 1 wherein J is J-3. Specifically preferred compounds of the invention for reasons of most efficient weed control and/or better cro tolerance are compounds of Formula 20 I selected from the group consisting of: ejtfi-2-[(2-bromo-3-thienyl)methoxy]-l-methyl-4- (1-methylethy1)-7-oxabicyclo[2.2.1]heptane; ££θ_-2-[(2-ethyl-3-thienyl)methoxy]-l-methyl-4- (1-methylethyl)-7-oxabicyclo[2.2.1]heptane; 25 and exo-2-r(2-methγl-3-thienyl)methoxy -1-methy1-4- (1-methylethyl)-7-oxabicyclo[2.2.1]heptane. DETAILED DESCRIPTION OF THE INVENTION 30 Many of the compounds of Formula I are known in the art. They can be prepared according to processes described in U.S. 4,670,041 and U.S. 4,486,219. Compounds of Formula I wherein Q is Q-3 and R^ Q is H, F or Cl can be prepared as described in Scheme 1. 35 gCHEME I (a) Room Temperature MMBBKK ((ccaatt..)) DMF (1) The bromide (1) can then be converted to compounds of Formula I wherein Rg is CH 3 , CH 2 CH 3 , F or Cl by lithiation, for example, with n-butyl lithium at -78 β C followed by treatment with « jnethylating or ethylating agent or an anion fluoridating or chlor¬ inating agent which are well known to one skilled in the art. When R 10 . is CH 3 , following the bromination with Br 2 (AIBN), Scheme lb, the desired product is first separated fran < t_he ώibromo derivatives or the alternate bromo metityl iswners -by -methods well known to one skilled in the art (e.g. chromatography), prior to reaction with JOH (Scheme lc) . Compounds of Foτmulβ I where Q is Q-4 and RIO is H, F or Cl can be pxepared βs described in Scheme 2. SUBSTlTϋtE SHEET DMF (2) Again, the bromide (2) can then be converted to compounds of Formula I wherein Rg is CH 3 , CH 2 CH 3 , F or Cl by lithiation followed by treatment with an alkylating or halogenating agent. When R 10 is CH 3 , the separation of the desired product of the bromina- tion of Scheme 2b from dibro ination and isomeric products will also be required prior to carrying out the reaction of Scheme 2c. All stereoisomers (diastereomers and enanti- o ers); SΏUΩ. and £22. forms; and mixtures thereof are included within the scope of the present invention. The various individual isomeric forms and various combinations of the derivatives usually have some difference in herbicidal or plant growth control properties. The following examples serve to illustrate the preparation of compounds of the invention: Example 1 2-Bromo-3-Methylthiophene To a solution containing 600 ml of chloroform, 600 ml of acetic acid, and 98.0 g of 3-methylthiophene was added portionwise 188.Og of N-Bromosuccinimide with stirring. The addition was exothermic and the reaction mixture was kept below 35°C by means of an ice bath. After the addition was complete, the reaction was allowed to sit for 30 minutes at room temperature whereupon 1.2L of water was added. The organic layer was separated, washed with 600ml of water, followed by 600 ml of X N NaOH, and finally 600 ml of water. The organic layer was dried over MgS0 4 , filtered, and the filtrate reduced to a tan oil. Fractional distillation afforded 128g of a yellow mobile oil boiling between 130°C and 170°C. S Example 2 2-Bromo-3-Bromomethylthiophene To a solution of 120.Og of 2-b omo-3-methyl- thiophene in 1000ml of carbon tetrachloride was added 0.5g of Azobisisobutyronitrile. The solution was 0 heated to reflux and 34.9 ml of bromine (Br 2 (l)) was added dropwise over a three hour period. After continued refluxing for 30 minutes, the mixture was cooled to room temperature, and washed with 500 ml portions of water, saturated NaHS0 3 (aq) and saturated 5 NaHC0 3 (aq). The organic layer was dried over MgS0 4 , filtered, and the filtrate reduced to a dark oil. Vacuum distillation afforded 86.8g of a yellow oil boiling between 80 and 92°C at 2 mm. The material was estimated to be 90% pure. 0 Example 3 ej & β-2-[(2-bromo-3-thienyl)methoxy]-1-methy1-4- (l-methvlethvn-7-oxabicvclor2.2.11heptane Sodium hydride (60% in oil, 13.5g) was washed with 30 ml of dry hexane under a nitrogen atmosphere. 25 To the washed sodium hydride was added 500 ml of anhydrous dimethylformamide followed by 52.Og of (±)-2-exo-hydroxy-l-methyl-4-isopropyl-7-oxabicyclo- [2.2.l]heptane. The resulting mixture was stirred for 2 hours at the end of which H 2 (g) evolution had 30 ceased. The mixture was cooled to -10°C and 86.8g of 2-bromo-3-bromomethyl thiophene was added portionwise keeping the temperature below 0°C. After the addition was complete, the mixture was allowed to warm to room temperature and stirred overnight. The mixture was 35 poured into 500ml of ice-water, extracted 3 times with ether and the combined ether extracts were washed 3 times with 200ml portions of water, dried over MgS0 4 , filtered and the filtrate concentrated to afford llOg of a brown oil. Flash chromatography over silica gel using 15% ethylacetate in hexane yielded 93g of a light brown oil. NMR( 1 H, 200MHz, CDCI3, ppm) (d - 7.2, 1H, J-6Hz, ArH) (d - 7.0, 1H, J-6HZ, ArH) (AB quartet, 4.4, 2H, J-llHz, OCH2) (m, 3.5, 1H, CH-0-) (S, 1.45, 3H/CH 3 ) (dd, 0.97, 6H, CH(CH 3 ) 2 ) (m, 1.9-2.2, 3H Aliphatic ring H's) (m, 1.4-1.6, 4H Aliphatic ring H's) Example 4 exo-2-f(2-me hyl-3-thienyl)methoxyl-l-methyl-4- (1-methvlethvl -7-oxabicvcloT2.2.11heptane To 1.5g (4.5 mmoles) of the compound of Example 3 in 25 ml of dry tetrahydrofuran, cooled to -78 β C, was added dropwise 2.0 ml of 2.55M n-butyl lithium in hexane, while maintaining the reaction temperature below -55 β C. Stirring was continued for an additional 10 minutes at -78°C, then 0.32 ml of methyl iodide was added and the mixture allowed to warm to room temperature and stirred overnight. The reaction mixture was poured into 100 ml of ice-water, extracted with 150 ml of ether, washed with water, dried over MgS0 4 , filtered and concentrated to yield 0.90g of a light yellow oil. It was shown to be 90% pure by NMR. NMR ( X H, 200MHz, CDC1 3 , ppm) (d - 7.0, 1H, J«CH 3 , ArH) (d - 6.93, 1H, J-6Hz, ArH (q - 4.4, 2H, OCH 2 ) (m - 3.5, 1H, CH-0-) (s - 2.42, 3H, -CH 3 ) (s - 1.44, 3H, -CH 3 ) (dd - 0.97, 6H, CH(CH 3 ) 2 ) (m - 1.4-2.3, 7H, Aliphatic ring H's) Formulations The method of this invention can be conveniently carried out by formulating a compound of Formula I in the conventional ways. They include dusts, granules, pellets, solutions, suspensions, emulsions, wettable powders, emulsifiable concentrates and the like. Many of these may be applied directly. Sprayable formula¬ tions can be extended in suitable media and used at spray volumes of from a few liters* to several hundred liters per hectare. High strength compositions are primarily used as intermediates for further formula¬ tion. The herbicidal formulations of the invention comprise 0.1% to 99% by weight of active ingredient(s) and at least one of (a) about 0.1% to 20% surfac- tant(s) and (b) about 1% to 99.9% solid or liquid inert diiuent(s). More specifically, they will con¬ tain these ingredients in the following approximate proportions: Weight Percent* Active Ingredient Diluent(s) Surfactant(s) Wettable Powders 20-90 0-74 1-10 Oil Suspensions, 3-50 40-95 0-15 Emulsions, Solutions, (including Emulsifiable Concentrates) Aqueous Suspension Dusts Granules and Pellets High Strength Compositions * Active ingredient plus at least one of a Surfactant or a Diluent equals 100 weight percent. Lower or higher levels of active ingredient can, of course, be present depending on the intended use and the physical properties of the compound. Higher ratios of surfactant to active ingredient are some¬ times desirable, and are achieved by incorporation into the formulation or by tank mixing. Typical solid diluents are described in Watkins, et al., "Handbook of Insecticide Dust Diluents and Carriers", 2nd Ed., Dorland Books, Caldwell, New Jersey, but other solids, either mined or manufac¬ tured, may be used. The more absorptive diluents are preferred for wettable powders and the denser ones for dusts. Typical liquid diluents and solvents are described in Marsden, "Solvents Guide," 2nd Ed., Interscience, New York, 1950. Solubility under 0.1% is preferred for suspension concentrates; solution concentrates are preferably stable against phase separation at 0 β C. "McCutcheon's Detergents and Emulsifiers Annual", MC Publishing Corp., Ridgewood, New Jersey, as well as Sisely and Wood, "Encyclopedia of Surface Active Agents", Chemical Publishing Co., SUBSTITUTESHEET Inc., New York, 1964, list surfactants and recommended uses. All formulations can contain minor amounts of additives to reduce foaming, caking, corrosion, micro¬ biological growth, etc. The methods of making such compositions are well known. Solutions are prepared by simply mixing the ingredients. Fine solid compositions are made by blending and, usually, grinding as in a hammer or fluid energy mill. Suspensions are prepared by wet milling (see, for example, Littler, U.S. Patent 3,060,084). Granules and pellets may be made by spraying the active material upon preformed granular carriers or by agglomeration techniques. See J. E. Browning, "Agglomeration", Chemical Engineering. December 4, 1967, pp. 147ff. and "Perry's Chemical Engineer's Handbook", 5th Ed., McGraw-Hill, New York, 1973, pp. 8-57ff. For further information regarding the art of formulation, see for example: H. M. Loux, U.S. Patent 3,235,361, February 15, 1966, Col. 6, line 16 through Col. 7, line 19 and Examples 10 through 41; R. W. Luckenbaugh, U.S. Patent 3,309,192, March 14, 1967, Col. 5, line 43 through Col. 7, line 62 and Examples 8, 12, 15, 39, 41, 52, 53, 58, 132, 138-140, 162-164, 166, 167 and 169-182; H. Gysin and E. Knusli, U.S. Patent 2,891,8.55, June 23, 1959, Col. 3, line 66 through Col. 5, line 17 and Examples 1-4; G. C. Klingman, "Weed Control as a Science", John Wiley and Sons, Inc., New York, 1961, pp. 81-96; and J. D. Fryer and S. A. Evans, "Weed Control Hand¬ book", 5th Ed., Blackwell Scientific Publications, Oxford, 1968, pp. 101-103. SUBSTITUTESHEET In the following Examples, all parts are by weight unless otherwise indicated. Example 5 Wettable Powder endo-4-[(2-fluorophenyl)methoxy]-5,7,7-tri- methyl-6-oxabicyclo[3.2.1]octane 50% sodium alkylnaphthalenesulfonate 2% low viscosity methyl cellulose 2% diatomaceous earth 46% The ingredients are blended, coarsely hammer- milled and then air-milled to produce particles essen- tially all below 10 microns in diameter. The product is reblended before packaging. Example 6 Granule Wettable Powder of Example 5 5% attapulgite granules 95% (U.S.S. 20 to 40 mesh; 0.84-0.42 mm) A slurry of wettable powder containing 25% solids is sprayed on the surface of attapulgite granules in a double-cone blender. The granules are dried and packaged. Example 7 Extruded Pellet £juϊ&-4-[(2-fluorophenyl)methoxy]-5,7,7-tri- methyl-6-oxabicyclo[3.2.1]octane 25% anhydrous sodium sulfate 10% crude calcium ligninsulfonate 5% sodium alkylnaphthalenesulfonate 1% calcium/magnesium bentonite 59% The ingredients are blended, hammer-milled and then moistened with about 12% water. The mixture is SUBSTITUTESHEET extruded as cylinders about 3 mm diameter which are cut to produce pellets about 3 mm long. These may be used directly after drying, or the dried pellets may be crushed to pass a U.S.S. No. 20 sieve (0.84 mm openings). The granules held on a U.S.S. No. 40 sieve (0.42 mm openings) may be packaged for use and the fines recycled. Exam l B Low Strength Granule endo-4-f(2-fluorophenyl)methoxy]-5.7,7-tri- methyl-6-oxabicyclo[3.2.1]octane 0.1% attapulgite granules 99.9% (U.S.S. 20 to 40 mesh) The active ingredient is dissolved in a solvent and the solution is sprayed upon dedusted granules in a double-cone blender. After spraying of the solution has been completed, the material is warmed to evaporate the solvent. The material is allowed to cool and then packaged. Example 9 L strength Granule endo-4-f(2-fluorophenyl)methoxy]-5,7,7-tri- methyl-6-oxabicyclot3.2.l]octane 1% N,N-dimethylformamide 9% attapulgite granules 90% (U.S.S. 20 to 40 sieve) The active ingredient is dissolved in the solvent and the solution is sprayed upon dedusted granules in a double cone blender. After spraying of the solution has been completed, the blender is allowed ±o run for a short period and then the granules are packaged. SUBSTITUTESHEET Example 10 Wettable Powder e_ι !_Q.-4-t(2-fluorophenyl)methoxy]-5,7,7-tri- methyl-6-oxabicyclo[3.2.1]octane 40% sodium ligninsulfonate 20% montmorillonite clay 40% The ingredients are thoroughly blended, coarsely hammer-milled and then air-milled to produce particles essentially all below 10 microns in size. The material is reblended and then packaged. Example 11 ,. Emulsifiable Concentrate endo-4-t(2-fluorophenyl)methoxy]-5,7,7-tri- methyl-6-oxabicyclo[3.2.1]octane 35% blend of polyalcohol carboxylic 6% esters and oil soluble petroleum sulfonates xylene 59% The ingredients are combined and filtered to remove undissolved solids. The product can be used directly, extended with oils, or emulsified in water. Example 12 Pust ejιd£-4-[(2-fluorophenyl)methoxy]-5,7,7-tri- methyl-6-oxabicyclo[3.2.1]octane 10% attapulgite 10% Pyrophyllite 80% The active ingredient is blended with attapul¬ gite and then passed through a hammer-mill to produce particles substantially all below 200 microns. The ground concentrate is then blended with powdered pyrophyllite until homogeneous. Example 13 wettable Powder endo-4-f(2-fluorophenyl)methoxy]-5,7,7-tri- methyl-6-oxabicyclo[3.2.1]octane 20% sodium alkylnaphthalenesulfonate 4% sodium ligninsulfonate 4% low viscosity methyl cellulose 3% attapulgite 69% The ingredients are thoroughly blended. After grinding in a hammer-mill to produce particles essen¬ tially all below 100 microns, the material is reblended and sifted through a U.S.S. No. 50 sieve (0.3 mm opening) and packaged. Utility Test results indicate that the compounds of the present invention are highly active pree ergent or poste ergent herbicides or plant growth regulants. They have utility for selective weed control in paddy rice fields containing japonica or indica rice. Compounds of this invention are particularly useful for the control of weeds in paddy rice. They may be applied postemergence to paddy rice or to rice from which the flood has been removed. They may also be applied to paddy rice after transplanting as a spray or granule. The application may be made from 3 to 10 days after transplanting. Rates of 16 to 1500 g/ha will provide weed control. The compounds are particularly useful for the control of barnyardgrass (Echinochloa crus-oa liϊ . a pernicious weed in rice culture, but may also provide complete or partial control of other weeds, particularly gramineous weeds, in rice. SUBSTITUTE SHEET The compounds of this invention may be used in combination with other commercial herbicides. They are particularly useful in combination with the following herbicides: methyl 2-[[[[(4,6-dimethoxy-2-pyrimidinyl) amino]carbonyl]amino]sulfonyl]methyl benzoate (bensulfuron methyl) ethyl 5-[3-(4,6-dimethoxypyrimidin-2-yl)ureido- suIfonyl]-1-methylρyrazole-4-carboxylate SUBSTITUTE SHEET Compounds Compound 1 Compound 2 25 Compound 3 35 SUBSTITUTE SHEET Compound 4 20 Compound 5 Compound B 10 30 6 Br 7 CH 3 8 CH 2 CH 3 35 SUBSTITUTE SHEET Example 14 Waxed paper cups with a top surface area of 100 cm 2 were partially filled with Tama silt loam soil. Either barnyardgrass or japonica rice seeds were planted into the soil in each pot, which was kept moist until the seedlings had reached the one leaf stage. Water was then added to a 3 cm depth and applications of chemical were made directly to the water after being formulated in a non-phytoxic solvent. Treatments were made at the 1.5-2.0 leaf stage of barnyardgrass and 1 leaf stage of rice. Visual evaluations of weed control and crop injury were made 14 days- after application. The test results are summarized in Table 1. SUBSTITUTE SHEET 10 15 20 25 30 35 continued) 10 15 20 25 30 35

Claims: WHAT IS CLAIMED IS: 1. The method for controlling the growth of undesired vegetation in a paddy rice crop which comprises applying to the locus of the paddy rice crop an effective amount of a compound of the formula: JOCH 2 Q wherein R χ is CH 3 or CH 2 CH 3 ; R 2 and R 3 are independently CH 3 or CH CH 3 or R 2 and R3 may be taken together as -(CH 2 ) n - where n is 4 or 5; R 4 is CH 3 or CH 2 CH 3 ; R 5 and R 6 are independently CH3 or CH 2 CH 3 ; R 7 is CH 3 or CH 2 CH 3 ; R 8 is CH 3 , CH 2 CH 3 or CH(CH 3 ) 2 ; 0=1 0=1 0=1 0= X and Y are independently H, F, Cl or CH 3 ; R 9 is F, Cl, Br, CH 3 or CH 2 CH 3 ; and R 10 is H, F, Cl or CH 3 ; provided that when J is J-3, then Q is Q-3 or Q-4. 2. The method of Claim 1 wherein R^ is CH 3 ; R 2 and R 3 are CH 2 CH 3 or R 2 and R 3 are taken together as -(CH 2 ) n - where n is 4 or 5; R 4 is CH 3 ; R5 and Rg are CH 3 ; R 7 is CH 3 ; and R 8 is CH(CH 3 ) 2 . 3. The method of Claim 1 wherein the crop is transplanted japonica rice. 4. The method of Claim 1 wherein the crop is transplanted indica rice. 5. The method of Claim 1 wherein among the weeds controlled is barnyardgrass. 6. The method of Claim 1 wherein the compound is Sl ώ fl -4-t(2-fluorophenyl)methoxy]-5,7,7-tri- methyl-6-oxabicyclo[3.2.l]octane. 7. The method of Claim 1 wherein the compound is 6-ejQ_d_-benzyloxy-1-methy1-3,3-tetramethylene- 2-oxabicyclo[2.2.2]octane. 8. The method of Claim 1 wherein the compound is 6-endo-benzyloxy-l-meth l-3,3-pentamethylene- 2-oxabicyclo[2.2.2]octane. 9. The method of Claim 1 wherein the compound is 6-endo-f(2-fluorophenyl)methoxy]-3,3-penta- methylene-2-oxabicyclo[2.2.2]octane. 10. The method of Claim 1 wherein the compound is l-methyl-3,3-diethyl-6-endo-[(2-fluoro- phenyl)methoxy]-2-oxabicyclo[2.2.2]octane. 11. The method of Claim 1 wherein the compound is S_ZΩ.-2-[(2-bromo-3-thienyl)methoxy]-1-methy1-4- (l-methylethyl)-7-oxabicyclo[2.2.1]heptane. 24 12 The method of Claim 1 wherein the compound is f iX f i . -2-[(2-ethyl-3-thienyl)methoxy]-l-methyl-4- (1-methylethyl)-7-oxabicyclo[2.2.1]heptane. 13, The method of Claim 1 wherein the compound is ejto_-2-t(2-methyl-3-thienyl)methoxy]-l-methyl- 4-(1-methylethyl)-7-oxabicyclo[2.2.1]heptan . 14 A compound of the formula: JOCH 2 Q wherein R 2 and R3 are independently CH3 or CH 2 CH3 or R 2 and R 3 may be taken together as -(CH 2 ) n - where n is 4 or 5; is CH-, or CH- > CH 3' R 5 and R 6 are independently CH 3 or CH 2 CH 3 ; R 7 is CH 3 or CH 2 CH 3 ; R 8 is CH 3 , CH 2 CH 3 or CH(CH 3 ) 2 ; R 9 is F, Cl, Br, CH 3 or CH 2 CH 3 ; and R 10 is H, F, Cl or CH3. 06 25 15. A compound of Claim 14 wherein R j^ is CH 3 ; R 2 and R 3 are CH 2 CH3 or R 2 and are taken together as -(CH 2 ) n - where n is 4 or 5; R 4 is CH 3 ; 5 and R 6 are CH 3 ; R 7 is CH 3 ; and R 8 is CH(CH 3 ) 2 . 16. A compound of Claim 15 wherein J is J-3. 17. The compound of Claim 16 which is S ZQ.-2-[(2-bromo-3-thienyl)methoxy]-1-methy1-4- (1-methylethyl)-7-oxabιcyclo[2.2.1]heptane. 18. The compound of Claim 16 which is f ixj l -2-[(2-ethyl-3-thienyl)methoxy]-l-methyl-4- (1-methylethyl)-7-oxabicyclo[2.2.1]heptane. 19. The compound of Claim 16 which is £XΩ.-2-[(2-methyl-3-thienyl)methoxy]-1-methy1- 4-(l-methylethyl)-7-oxabicyclo[2.2.l]heptane. 20. A composition suitable for controlling the growth of undesired vegetation which comprises an effective amount of a compound of Claim 14 and at least one of the following: surfactant, solid or liquid diluent. 21. A composition suitable for controlling the growth of undesired vegetation which comprises an effective amount of a compound Q of Claim 15 and at least one of the following: surfactant, solid or liquid diluent. 22. A composition suitable for controlling the growth of undesired vegetation which 5 comprises an effective amount of a compound of Claim 16 and at least one of the following: surfactant, solid or liquid diluent. 23. A composition suitable for controlling the growth of undesired vegetation which comprises an effective amount of the compound of Claim 17 and at least one of the following: surfactant, solid or liquid diluent. 24. A composition suitable for controlling the growth of undesired vegetation which comprises an effective amount of the compound of Claim 18 and at"least one of the following: surfactant, solid or liquid diluent. 25. A composition suitable for controlling the growth of undesired vegetation which comprises an effective amount of the compound of Claim 19 and at least one of the following: surfactant, solid or liquid diluent. 26. A composition suitable for controlling the growth of undesired vegetation in the locus of a rice paddy which comprises an effective amount of a compound of Claim 14 and at least one of the following: surfactant, solid or liquid diluent.

Inventors: BOZARTH GENE ALLEN, CHRISTENSEN JOEL ROBERT, POWELL JAMES EDWARD, BOZARTH, GENE, ALLEN, CHRISTENSEN, JOEL, ROBERT, POWELL, JAMES, EDWARD
Applicants: DU PONT, E.I. DU PONT DE NEMOURS AND COMPANY
Application year: 1988
Main classification: A01N43
IPC codes: A01N43, C07D307, C07D403, C07D409, C07D493