*3.7. Dehydration under Basic Conditions* (**3dc**)

To a stirred solution of the alcohol **8dc** (15.3 mg, 0.0355 mmol) in CH2Cl2 (1.0 mL) was added NEt3 (40 μL, 0.29 mmol, 8 equiv.), MsCl (10 μL, 0.13 mmol, 3.7 equiv.), and DMAP (1.1 mg, 9.0 μmol, 0.25 equiv.) at rt. After stirring for 1 h, the reaction mixture was diluted with sat. aq. NH4Cl (5 mL) and EtOAc (30 mL). The organic layer was separated, dried over Na2SO4, filtered, and concentrated under reduced pressure. The crude residue was purified by column chromatography (silica gel, Hexane:EtOAc:CH2Cl2 = 4:1:1) to afford aldol adduct **3dc** (11.6 mg, 0.0281 mmol, 79% yield).
