反应详情

To the dihydroxy ester from Step 15 (6.8 g, 15.4 mmol) in EtOAc (150 mL) at 50° C. was added MnO2 (6.7 g, 76.8 mmol). After stirring for 30 minutes at 50° C. more MnO2 (6.7 g) was added, and 30 minutes later, a third portion of MnO2 (6.7 g) was added. An hour later, the warm reaction mixture was filtered through celite and the cake was washed with additional EtOAc. Evaporation of the solvents gave the title aidehyde 5.62 g (83%). 1H NMR (CD3COCD3): δ5 10.4 (1H, s), 7.9 (1H, br s), 7.8 (2H, m), 7.58 (1H, t), 7.38 (1H, br d), 7.1 (3H, m), 4.1 (1H, t), 3.54 (3H, s), 3.13 (1H, ddd), 2.85 (1H, ddd), 2.51 (2H, s), 2.49 (2H, d), 2.2 (2H, m), 1.51 (6H, s), 0.52-0.32 (4H, m).

1. additionwas added
2. customAn hour later, the warm reaction mixture
3. filtrationwas filtered through celite
4. washthe cake was washed with additional EtOAc
5. customEvaporation of the solvents
6. customgave the title aidehyde 5.62 g (83%)