反应详情

A slow stream of O3 in O2 was passed through a −78° C. cooled solution of 3-(1-((tert-butyldimethylsilyl)oxy)ethyl)-4-vinyl-1H-isochromen-1-one (intermediate B59.1, 2.967 g of crude) in DCM (100 ml) for 1.5 hrs. The excess of 03 was purged by N2 bubbling, then a solution of PPh3 (2.316 g, 8.83 mmol) in DCM (20 ml) was added. The solution was allowed to reach 25° C. and it was stirred overnight. The solvent was removed in vacuo and the crude material was purified by flash chromatography on Biotage silica gel cartridge (cyclohexane to cyclohexane:EtOAc=90:10) to afford 3-(1-((tert-butyldimethylsilyl)oxy)ethyl)-1-oxo-1H-isochromene-4-carbaldehyde (Intermediate B59.2, 1.453 g, 4.38 mmol).

1. customwas passed through a −78° C.
2. customThe excess of 03 was purged by N2 bubbling
3. customto reach 25° C.
4. customThe solvent was removed in vacuo
5. customthe crude material was purified by flash chromatography on Biotage silica gel cartridge (cyclohexane to cyclohexane:EtOAc=90:10)