反応 #469431

反応方程式

2

1,2,3,6-Tetra-O-acetyl-4-O-(3,4,6-tri-O-acetyl-2O-allyl-β-D-galactopyranosyl)-α,β-D-glucopyranose

CH2Cl2

→

3

収率 85.0%

2,3,6-Tri-O-acetyl-4-O-(3,4,6-tri-O-acetyl-2-O-allyl-β-D-galactopyranosyl)-α-D-glucopyranosyl choride

収率 85.0%

反応条件

後処理

1. 1
   濃縮concentrated
2. 2
   その他the residue was chromatographed on silica gel with pentane-EtOAc (6:4)

実験手順

To a solution of 2 (3.5 g, 5.17 mmol) in CH2Cl2 (10 mL) Cl2CHOCH3 (0.56 mL, 6.2 mmol) and ZnBr2 (100mg) were added under an Ar atmosphere. The mixture was stirred for 1 h, then concentrated and the residue was chromatographed on silica gel with pentane-EtOAc (6:4) to give 3 (396 mg, 85%), [α]D+93.4° (c 1.2, CHCl3); 1H NMR (CDCl3) δ 6.22 (s, 1H, J1,2=3.9 Hz, H-1), 5.80 (m, 1H, Hc), 5.56 (t, 1H, J3,4 and J2,3≈9.7 Hz, H-3), 5.31 (dd, 1H, J4′,3′=3.5 Hz, J4′,5′=0.8 Hz, H-4′), 5.20 (1H, Hb), 5.12 (1H, Ha), 4.93 (dd, 1H, H-2),4.86(dd, 1H, J2′,3′=10.2 Hz, H-3′), 4.58 (dd, 1H, J6a,6b=12.1 Hz, J5,6a=0.7 Hz, H-6a), 4.34 (d, 1H, J1′,2′=7.7 Hz, H-1), 4.29 (dd, 1H, J5,6b =4.2 Hz, H-6B),4.25-4.01 (m, 5H, Hd, He, H-5, H-6′a, H-6′b), 3.85-3.78 (m, 2H, H-4, H-5′), 3.42 (dd, 1H, H-2′). Calc'd for C27H37Cl16 (653.025) C, 49.66; H, 5.71, Cl, 5.43. Found C, 49.68, H, 5.68, Cl, 5.73.

出典