5-methyl-2-oxohexanoic acid

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: reacting 5-methyl-2-oxohexanoic acid with at least a 10% excess of the stoichiometric amount of oxalyl chloride under anhydrous conditions at a temperature of 25° to 60° C. for from 40 to 60 hours to form 5-methyl-2-oxohexanoyl chloride; at a temperature of 25° to 60° C. for from 40 to 60 hours

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

Procedure: reacting 5-methyl-2-oxohexanoic acid with at least a 10% excess of the stoichiometric amount of oxalyl chloride under anhydrous conditions at a temperature of 25° to 60° C. for from 40 to 60 hours to form 5-methyl-2-oxohexanoyl chloride; at a temperature of 25° to 60° C. for from 40 to 60 hours

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

Procedure: The 5-methyl-2-oxohexanoic acid is reacted with at least a 10% excess over the stoichiometric amount of oxalyl chloride to form 5-methyl-2-oxohexanoyl chloride [reaction (4)]. ##EQU6## Oxalyl chloride is a suitable solvent for reaction (4), and theoretically can be present in an unlimited excess over stoichiometry. Solvents such as diethyl ether, petroleum ether, benzene, CH2Cl2, and hexane are also suitable solvents for the reaction. The use of solvents is preferred but is not necessary. Reaction (4) must be run under anhydrous conditions in an inert atmosphere and requires from 40 to 60 hours at a temperature of from 25° to 60° C. for completion.

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

Procedure: t-Butyl 5-methyl-2-oxohexanoate is readily hydrolyzed under suitably mild conditions at room temperature (i.e., 25°-30° C.). Suitable reactions include hydrolysis directly to the acid form using trifluoracetic acid [reaction (3)] or hydrolysis with dilute bases such as sodium or potassium hydroxide followed by acidification with dilute mineral acids such as hydrochloric, sulfuric, or nitric acids. ##EQU5## Trifluoroacetic acid can be used as a solvent for the reaction shown (3). When trifluoroacetic acid is the hydrolyzing reagent, this step can be accomplished before the hydrogenation step. The acid is recovered by volatization of the trifluoroacetic acid. If hydrolysis is done with dilute base, followed by acidification with mineral acid, the acid is then extracted in the same manner as described for the extraction of the ester in step (a). is readily hydrolyzed under suitably mild conditions at room temperature (i.e., 25°-30° C.) hydrolysis directly to the acid form The acid is recovered by volatization of the trifluoroacetic acid If hydrolysis with dilute base the acid is then extracted in the same manner as described for the extraction of the ester in step (a)

Conditions: temp:-15.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 5-methyl-2-oxohexanoic acid (0.288 g.) in methylene chloride (1 ml.) was added during 15 minutes to a stirred solution of dicyclohexylcarbodiimide (0.412 g.) and benzyl alcohol (0.432 g.) in methylene chloride (10 ml.) which was cooled to -15° C., and the mixture was stirred at that temperature for 1 hour, then at laboratory temperature for 30 minutes, and was then evaporated to dryness. Water (1 ml.), diethyl ether (2 ml.) and acetic acid (0.01 ml.) were added and the mixture was kept at laboratory temperature for 12 hours and then evaporated to dryness. The residue was purified by chromatography on a silica gel column using toluene as eluant and there was thus obtained benzyl 5-methyl-2-oxohexanoate as an oil. at laboratory temperature for 30 minutes was then evaporated to dryness Water (1 ml.), diethyl ether (2 ml.) and acetic acid (0.01 ml.) were added the mixture was kept at laboratory temperature for 12 hours evaporated to dryness The residue was purified by chromatography on a silica gel column

Conditions: temp:-15.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 5-methyl-2-oxohexanoic acid (0.288 g.) in methylene chloride (1 ml.) was added during 15 minutes to a stirred solution of dicyclohexylcarbodiimide (0.412 g.) and benzyl alcohol (0.432 g.) in methylene chloride (10 ml.) which was cooled to -15° C., and the mixture was stirred at that temperature for 1 hour, then at laboratory temperature for 30 minutes, and was then evaporated to dryness. Water (1 ml.), diethyl ether (2 ml.) and acetic acid (0.01 ml.) were added and the mixture was kept at laboratory temperature for 12 hours and then evaporated to dryness. The residue was purified by chromatography on a silica gel column using toluene as eluant and there was thus obtained benzyl 5-methyl-2-oxohexanoate as an oil. at laboratory temperature for 30 minutes was then evaporated to dryness Water (1 ml.), diethyl ether (2 ml.) and acetic acid (0.01 ml.) were added the mixture was kept at laboratory temperature for 12 hours evaporated to dryness The residue was purified by chromatography on a silica gel column

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: reacting 5-methyl-2-oxohexanoic acid with at least a 10% excess of the stoichiometric amount of oxalyl chloride under anhydrous conditions at a temperature of 25° to 60° C. for from 40 to 60 hours to form 5-methyl-2-oxohexanoyl chloride; at a temperature of 25° to 60° C. for from 40 to 60 hours

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

Procedure: reacting 5-methyl-2-oxohexanoic acid with at least a 10% excess of the stoichiometric amount of oxalyl chloride under anhydrous conditions at a temperature of 25° to 60° C. for from 40 to 60 hours to form 5-methyl-2-oxohexanoyl chloride; at a temperature of 25° to 60° C. for from 40 to 60 hours

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

Procedure: The 5-methyl-2-oxohexanoic acid is reacted with at least a 10% excess over the stoichiometric amount of oxalyl chloride to form 5-methyl-2-oxohexanoyl chloride [reaction (4)]. ##EQU6## Oxalyl chloride is a suitable solvent for reaction (4), and theoretically can be present in an unlimited excess over stoichiometry. Solvents such as diethyl ether, petroleum ether, benzene, CH2Cl2, and hexane are also suitable solvents for the reaction. The use of solvents is preferred but is not necessary. Reaction (4) must be run under anhydrous conditions in an inert atmosphere and requires from 40 to 60 hours at a temperature of from 25° to 60° C. for completion.