Hexane → HCID 11416350, compound

Participants

Reaction Conditions

Reaction Steps

An oven dried three-necked 2 L round bottom flask was equipped with a mechanical stirrer, a thermometer, an N2 inlet, and a septum. The flask was charged with 180.71 g (0.689 mol) of triphenylphosphine and 925 mL of CH2Cl2. The reaction mixture was stirred under an N2 atmosphere and cooled to 0-5° C. with an external ice-water bath. The septum was then removed and 114.25 g (0.344 mol) of carbon tetrabromide was added in portions through the open neck of the flask at a rate that maintained the temperature of the reaction mixture below 20° C. After the addition was complete the reaction was stirred for 1 h and then a solution of the (S)-3-benzyloxy-2-methylpropanal from the previous step dissolved in 150 mL of CH2Cl2 was added via cannula over a 5 min period. The reaction mixture was stirred under N2 for an additional 1 h and allowed to warm to room temperature. A separate 10 L three-necked round bottom flask was equipped with a mechanical stirrer and charged with 4 L of hexane. The stirrer was started and the crude reaction mixture was introduced as a slow stream which resulted in formation of a granular precipitate. After the transfer was complete the reaction mixture was filtered and the solids were carefully washed with hexane. The filtrate was evaporated in vacuo and additional solids were deposited. The residue was resuspended in hexane, filtered and the filtrate reevaporated. The resulting oil was purified by Kugelrohr distillation to afford 46.54 g (81% for two steps) of the title compound as an oil.

Provenance & Evidence