To a stirring solution of #113 (2.10 g, 2.46 mM) in 10 mL of THF, lithium hydroxide (228 mg, 5.16 mM) was added followed by 3 mL of water. The reaction was allowed to stir at room temperature for 2 hours. The reaction was acidified though the addition of 1 M HCl and then concentrated in vacuo. The resulting white solid was taken up in 20 mL of acetonitrile and mL of water. The aqueous layer removed and the organic layer was washed once with water. The organic layer was dried over sodium sulfate, filtered, and concentrated in vacuo. Ethyl acetate (20 mL) was then added and the crude solid was allowed to stir for 30 minutes, before being filtered to yield a white solid #250 (1.42 g, 94%). LC-MS (Protocol Q): m/z 619.5 [M+H+], retention time=1.10 minutes. HPLC (Protocol A at 45° C.) m/z 619.4 [M+H+], retention time=6.732 minutes.
