反应详情

To the solution of (4R,6S)-4-(tert-butyldimethylsilyloxy)-6-(iodomethyl)-tetrahydropyran-2-one (6a) (40.00 g, 108.0 mmol) in AcOH (660 mL) is added AgOAc (20.03 g, 118.8 mmol). The resultant mixture is then heated at 125° C. for 6 hours. The reaction mixture is filtered through diatomite filter medium (Celite®). The obtained filtrate is evaporated to afford the residue. To this residue EtOAc (500 mL) and water (600 mL) are added. The organic layer is separated and the aqueous layer is washed again with EtOAc (5×150 mL). The combined organic layers are washed with water (4×300 mL), brine (5×300 mL) and dried over anhydrous MgSO4, filtered and concentrated under the reduced pressure to afford 30.28 g (92.6%) of ((2S,4R)-4-(tert-butyldimethylsilyloxy)-6-oxo-tetrahydro-2H-pyran-2-yl)methyl acetate (7) as yellow oil (HPLC purity 98%). 1H NMR (300 MHz, CDCl3): δ 4.93 (m, 1H), 4.37 (m, 1H), 4.30 (dd, J=12 Hz, J=3 Hz, 1H), 4.21 (dd, J=12 Hz, J=5 Hz, 1H), 2.62 (d, J=4 Hz, 2H), 2.11 (s, 3H), 1.84−1.80 (m, 2H), 0.89 (s, 9H), 0.09, 0.09 (2s, 6H). 13C NMR (75 MHz, CDCl3): δ 170.4, 169.1, 73.3, 65.5, 63.0, 38.9, 32.2, 20.5, 17.7, −5.1, −5.2.

1. filtrationThe reaction mixture is filtered through diatomite
2. filtrationfilter medium (Celite®)
3. customThe obtained filtrate is evaporated
4. customto afford the residue
5. customThe organic layer is separated
6. washthe aqueous layer is washed again with EtOAc (5×150 mL)
7. washThe combined organic layers are washed with water (4×300 mL), brine (5×300 mL)
8. dry with materialdried over anhydrous MgSO4
9. filtrationfiltered
10. concentrationconcentrated under the reduced pressure