Methyl hexanoate → HCID 178443801, compound

Participants

Reaction Conditions

Reaction Steps

In 12 ml of anhydrous tetrahydrofuran (THF) was dissolved 1.02 ml of diisopropylamine, and 4.8 ml of a 1.58M solution of n-butyl lithium in hexane was added to the solution at -40° C. in an argon atmosphere, and the mixture was stirred for 20 minutes and cooled to -78° C. A solution of 0.92 g of methyl hexanoate in 12 ml of anhydrous THF was added dropwise into the mixture over a period of 1 hour. The mixture was stirred for 20 minutes, and about 3 ml of a solution of 1.0 g of (S)-4-iodobutane-1,2-glycolactonide synthesized from (S)-1,2,4-butanetriol and 1.3 g of hexamethylphosphoramide in THF was added to the mixture. Then, the mixture was stirred at -40° C. for 3 hours, a saturated aqueous solution of ammonium chloride was added to the mixture, the mixture was extracted with ether, and the ether extract was washed with water and dried over magnesium sulfate. The solvent was removed by distillation and the obtained crude product was purified by the silica gel column chromatography to obtain 0.9 g of methyl 2-butyl-5,6-dihydroxyhexanoate acetonide. The obtained compound was treated with 4N hydrochloric acid in a 1/1 mixed solvent of methanol/water and hydrolyzed with an equivalent amount of potassium hydroxide. The majority of methanol was removed by distillation, and the residual mixture was made acidic and extracted with chloroform. The chloroform extract was washed with water and dried over magnesium sulfate. The solvent was removed by distillation, the obtained crude product was dissolved in benzene, and a catalytic amount of p-TsOH was added to the solution. The solution was refluxed for 3 hours and cooled. Then, the benzene solution was washed with an aqueous solution of sodium hydrogen carbonate and a saturated aqueous solution of sodium chloride and dried, the solvent was removed by distillation, and the obtained crude product was purified by the silica gel column chromatography to obtain 0.4 g of (S)-2-butyl-5-hydroxymethyl-δ-valerolactone. The obtained compound was dissolved in 20 ml of benzene, 0.8 g of 4-(4'-octyloxy)biphenol was added to the solution, and 1 g of triphenylphosphine and 0.9 g of diethyl azodicarboxylate were further added. Reaction was carried out at room temperature overnight. The reaction product was concentrated under a reduced pressure and purified by the silica gel column chromatography to obtain 0.6 g of (2R,5S)-2-butyl-5-(4'-octyloxybiphenyloxymethyl)-δ-valerolactone. The obtained compound was fractionated and purified by HPLC to obtain 0.2 g of (2R,5S)-2-butyl-5-(4'-oxtyloxybiphenyloxymethyl)-δ-valerolactone and 0.2 g of (2S,5S)-2-butyl-5-(4'-octyloxybiphenyloxymethyl)-δ-valerolactone. These compounds showed the following phase transitions. ##STR36##

Provenance & Evidence