Column chromatography (ethyl acetate/hexanes 1:9) provided compound E as a white solid. HPLC showed a single diastereoisomer. The white solid was dried under high vacuum yielding 1.71 g (3.70 mmol, 78% yield) as a white solid. 1H NMR (CDCl3) 400 MHz δ 7.42-7.35 (m, H), 7.25-...