C([O:8][CH2:9][CH:10]1[O:15][C:14](C)=[CH:13][C:12](=[O:17])[CH2:11]1)C1C=CC=CC=1.[CH3:18]COC(C)=O>[Pd]>[CH3:18][C:10]12[O:15][CH:14]([O:8][CH2:9]1)[CH2:13][C:12](=[O:17])[CH2:11]2A solution of 4.4 g of the 6-Benzyloxy compound from Step 2 in EtOAc was hydrogenated with H2 and Pd/C (10%). After completion, the reaction was filtrated on a bed of celite and then evaporated to dryness. The cru syrup was then taken up in CH2Cl2 containing 1 g of camphor sulphonic acid. The reaction was stirred at r.t. overnight, filtered and evaporated. Purification by flash chromatography (30% Et2O/pentane) gave 780 mg of the title compound (30%).
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