3-methylpentanedioic acid

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 80 g. of the methyl half ester of 3-methylglutaric acid (Linstead, lunt and Weedon, J. Chem. Soc. 1950, 3331) was converted to methyl 4-bromo-3-methylbutyrate as described by Marks and Polgar, J. Chem. Soc. 1955, 3854. The bromoester (51 g.) was reduced with sodium bis (2-methoxyethoxy)aluminum hydride in a mixture of toluene and ether yielding 43 g. of 4-bromo-3-methylbutyraldehyde. The aldehyde and 49 g. of 5-chlorosalicylhydroxamic acid were condensed by the method described in Example 1 and the product was ring-closed with 10 percent aqueous sodium hydroxide to give 8-chloro-3-methyl-2,3,4,4a-tetrahydro-10H-1,2-oxazino(3,2-b) (1,3)benzoxazin-10-one which melted at 121- 140° C. after recrystallization from ethanol. condensed by the method

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 80 g. of the methyl half ester of 3-methylglutaric acid (Linstead, lunt and Weedon, J. Chem. Soc. 1950, 3331) was converted to methyl 4-bromo-3-methylbutyrate as described by Marks and Polgar, J. Chem. Soc. 1955, 3854. The bromoester (51 g.) was reduced with sodium bis (2-methoxyethoxy)aluminum hydride in a mixture of toluene and ether yielding 43 g. of 4-bromo-3-methylbutyraldehyde. The aldehyde and 49 g. of 5-chlorosalicylhydroxamic acid were condensed by the method described in Example 1 and the product was ring-closed with 10 percent aqueous sodium hydroxide to give 8-chloro-3-methyl-2,3,4,4a-tetrahydro-10H-1,2-oxazino(3,2-b) (1,3)benzoxazin-10-one which melted at 121- 140° C. after recrystallization from ethanol. condensed by the method

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In 50 ml of toluene were dissolved 7.31 g (0.05 mole) of monomethylglutaric acid, 4.43 g (0.085 mole) of furan and 14.39 g (0.06 mole) of dichloroacetic anhydride. To the resulting solution was added 0.71 g of boron trifluoride-diethyl ether complex and the resulting mixture was then stirred at 50° C. for 3 hours. After completion of the reaction, the reaction solution was cooled and washed successively with 5% aqueous sodium carbonate solution and water. The organic layer was concentrated under reduced pressure and the resulting concentrated residue was then purified by silica gel-filled column chromatography to obtain 9.54 g of 2-(4-methoxycarbonylbutyryl)furan. To the resulting solution was added 0.71 g of boron trifluoride-diethyl ether complex After completion of the reaction the reaction solution was cooled washed successively with 5% aqueous sodium carbonate solution and water The organic layer was concentrated under reduced pressure the resulting concentrated residue was then purified by silica gel- filled column chromatography