反応 #40283

反応方程式

NaCl

Camphor sulfonic acid

p-anisaldehyde-dimethoxy-acetal

Pantothenic acid

→

3-{[2-(4-Methoxy-phenyl)-5,5-dimethyl-[1,3]dioxane-4-carbonyl]-amino}-propionic acid

収率 51.0%

溶媒

DCM

反応条件

後処理

1. 1
   その他The crude reaction product
2. 2
   濃縮was concentrated
3. 3
   その他purified silica gel chromatography (6:1 hexane:EtOAC-EtOAc)
4. 4
   その他to yield a white solid (8A1) (3.8 g, 51% yield)

実験手順

Pantothenic acid (7) (4.6 g, 2.24×10−2 mols) was dissolved in dry DCM (30 mL). Camphor sulfonic acid (0.52 g, 2.24×10−3 mols) and p-anisaldehyde-dimethoxy-acetal (3.82 mL, 2.24×10−2 mols) were added to the reaction mixture. The reaction was stirred overnight at room temperature with a drying tube. The crude reaction product was concentrated and purified silica gel chromatography (6:1 hexane:EtOAC-EtOAc) to yield a white solid (8A1) (3.8 g, 51% yield). mp=135-136° C. 1HNMR (400 MHz, DMSO) 0.93 (s, 3H), 0.99 (s, 3H), 2.38 (t, 2H, J=6.8 Hz), 3.25 (m, 1H), 3.34 (m, 1H), 3.5.9 (d, 1H, J=10.8 Hz), 3.62 (d, H, J=10.8 Hz), 3.74 (s, 3H), 4.07 (s, 1H), 5.50 (s, 1H), 6.91 (d, 2H, J=8.8 Hz), 7.41 (d, 2H, J=8.8 Hz). 13C-NMR (400 Mz, DMSO) 19.7, 22.2, 33.2, 34.4, 34.9, 55.8, 78.0, 83.8, 101.1, 114.0, 128.4, 131.1, 160.3, 168.9, 173.8. IR (NaCl, thin film), 3420, 2959, 1729, 1654, 1617, 1540, 1520, 1251, 1105 cm−1. MS (ESI) [M+Na]+360.1. HRMS (FAB) (m/z): [M+H]+ calcd for C17H23O6N, 338.1598, found 338.1594.

出典