反应详情

The procedure is analogous to that described in Example 8a), but starting with 0.79 g of [2,3,4-trihydroxy-phenyl][3',5'-dihydroxy-4'-(2-oxo-2-phenylethoxy)phenyl] methanone (compound VIIIb described in Example 2), 12.10 g of Tris and 2.30 g of silver oxide (Ag2O). After purification by chromatography on a 30 g silica gel column (diameter: 2.0 cm, height: 60 cm) eluted with an ethyl acetate/methanol mixture (97/3 by volume), 0.40 g of (RS)-5-[3,5-dihydroxy-4-(2-oxo-2-phenylethoxy)-benzoyl]-3,3-bis(hydroxymethyl)-8a-hydroxy-3,4-dihydro-2H-1,4-benzoxazin-8(8aH)-one is obtained in the form of an orange powder melting at around 185° C. (with decomposition).

1. customAfter purification by chromatography on a 30 g silica gel column (diameter: 2.0 cm, height: 60 cm)
2. washeluted with an ethyl acetate/methanol mixture (97/3 by volume)