A mixture of Intermediate 153d (0.53 g, 1.09 mmol) in dry THF (8 mL) was treated with triphenylphosphine (0.57 g, 2.18 mmol) and 2-(tetrahydro-2H-pyran-2-yloxy)ethanol (0.22 mL, 1.64 mmol). The mixture was cooled to 0° C. then diisopropylazodicarboxylate (0.43 mL, 2.18 mmol) was added dropwise. After stirring at ambient temperature for 20 h the mixture was treated with water (0.1 mL) and concentrated in vacuo to a yellow oil. The oil was purified by FCC, using 0-30% EtOAc in cyclohexane, to give the title compound as an orange oil (0.41 g, 61%). LCMS (Method 3): Rt 5.25 min, m/z 614.6 [MH+].
