“…The crude residue was purified by column chromatography on silica gel (60% EtOAc in hexane) to give MOM protected lactone 10a (300 mg, 95%) as a yellow amorphous solid. 2,152.9,137.5,131.1,104.2,97.4,95.1,83.7,76.6,60.8,56.1,55.2,40.4,21.2;LRMS (ESI) 4,152.8,132.14,129.8,104.4,98.0,95.2,86.4,75.4,60.8,56.0,55.2,39.3,21.4;LRMS (ESI) 5,153.1,138.0,129.9,103.8,86.0,71.5,60.8,56.1,40.2,25.3,17.7,LRMS (ESI) 3,152.7,137.5,131.7,104.6,97.9,85.2,73.7,60.7,56.0,43.1,25.4,21.2,17.8, 2, 137.9, 129.3, 103.5, 93.9, 84.6, 74.0, 71.4, 67.0, 60.8, 58.9, 56.1, 37.4; LRMS (ESI) 379.4 [M+Na] + .…”