Benzaldehyde dimethyl acetal → HCID 71153404, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of (3aR,4R,5R,6R,7aS)-4,5-dihydroxy-6-(hydroxymethyl)hexahydrobenzo[d]oxazol-2(3H)-one (2.99 g, 14.7 mmol) in DMF (10 mL) at room temperature was added p-toluenesulfonic acid monohydrate (210 mg, 1.10 mmol) followed by benzaldehyde dimethylacetal (6.72 g, 44.2 mmol). The mixture was heated at 60° C. under slightly diminished pressure for 3.5 h. After cooling, the reaction was diluted with water (100 mL) and extracted with EtOAc (2×60 mL). The extracts were washed with brine and dried with MgSO4. The solvent was evaporated to give the crude product. This was purified by silica gel column, eluted with 10-30% EtOAc in hexanes to provide (3aR,4R,4aR,8aR,9aS)-4-hydroxy-3-(methoxy(phenyl)methyl)-6-phenyloctahydro-2H-[1,3]dioxino[5′,4′:4,5]benzo[1,2-d]oxazol-2-one (3.33 g, 55%). MS m/z 434.6 (M+23, 100%); 1H NMR (400 MHz, CDCl3) δ 7.30-7.51 (m, 10H), 6.20 (s, 1H), 5.52 (s, 1H), 4.47-4.50 (m, 1H), 4.24 (dd, J=11.1 Hz, 4.7 Hz, 1H), 4.17 (d, J=2.5 Hz, 1H), 3.83-3.88 (m, 1H), 3.69 (s, 3H), 3.55 (t, J=11.0 Hz, 1H), 3.40 (t, J=10.1 Hz, 1H), 3.26 (t, J=6.8 Hz, 1H), 2.11-2.23 (m, 2H), 1.28-1.36 (m, 1H).

Provenance & Evidence