Dimethyl Sulfoxide → 3-(1-Decyl)-5-isoxazolecarboxaldehyde

To a solution of oxalyl chloride (31.7 ml) in dry dichloromethane (100 ml) cooled to -60° C., was added a solution of dimethylsulfoxide (9.8 ml) in dichloromethane (30 ml) followed by a slurry of 3-(1-decyl)-5-isoxazolemethanol (13.8 g) in dry dichloromethane (100 ml). The reaction mixture was stirred at -60° C. for 0.5 hr, quenched with triethylamine (40 ml), and allowed to warm to ambient temperature. The solution was poured into water (300 ml) and extracted with dichloromethane. The organic phases were washed with dilute citric acid, dried, and evaporated. The residue was flash chromatographed (silica, 50:1-dichloromethane:methanol). The appropriate fraction were collected and evaporated. The residue was recrystallized from ether-hexane to give 11.2 g (82%) of product, mp 46°-48° C.