Example 1
The SM (70 g, 300 mmol) was dissolved in hexanes (600 mL) and cooled to -78 C. A separate flask was charged with DIBAL-H (1.0 M in hexanes, 310 mmol) and also cooled to -78 C. The DIBAL-H solution was transferred via cannula over 20-25 min then stirred at -78 C for 1 h. The reaction mixture was quenched by adding MeOH (30 mL) and stirred at -78 C for 15 min. The cold solution was transferred to a 2L flask containing a saturated Rochelle salt solution (600 mL) and stirred for 3.5 h. The aq phase was separated and extracted further with hexane (200 mL). The combined org layers were washed with brine (100 mL), dried (MgSO4), filtered, and concentrated to provide the product. [91%]