Lactol 23(40.0 mg, 0.109 mmol) was dissolved in 4 mL toluene. Vinyl magnesium bromide (1.56 mL, 1.09 mmol) in 0.7 M THF was added at 0 degrees C and then warmed to 60 degrees C for 5 hours. The reaction was quenched with NaHCO3 (10 mL), extracted with EtOAc (3 x 10 mL), dried with anhydrous MgSO4 and dissolved in dichloromethane (5 mL). Et3N (218 mg, 2.15 mmol), 4-DMAP (13.0 mg, 0.109 mmol) and Ac2O (108 mg, 1.08 mmol) were added at 0 oC. The reaction was warmed to 40 degrees C and allowed to stir for 5 hours. It was again quenched with 10 mL of NaHCO3, extracted with EtOAc (3 x 20 mL), and dried over anhydrous MgSO4. Flash column chromatography was performed using EtOAc/petroleum ether (1:6) to get the diacetate, which was then put into 3 mL of toluene. Pd(Ph3)4 (37.0 mg, 0.0302 mmol) and HCO2NH4 (69.0 mg, 1.09 mmol) were added and the reaction was heated to 80 degrees C for 40 minutes. After cooling to 22 degrees C, the solvent was removed by vacuum and the remaining residue was purified by flash chromatography with EtOAc/petroleum ether (1:10). Acetate 24 was obtained as colorless foam (24.8 mg, 54% yield). IR (film): νmax = 3412, 3084, 2956, 2928, 2851, 1728, 1640, 1456, 1391, 1366, 1262, 1244, 1174, 1096, 1020, 968, 894, 740 cm-1.