2-O-(2-Deoxy-2-N-phthalimido-3,4,6-tri-O-acetyl--D-glucopyranosyl)-3-O-benzyl-4,6-O-benzylidene-D-mannose synthesis

Yield:865488-82-0 57%

Reaction Conditions:

with silver trifluoromethanesulfonate in nitromethane at -20 - 20; for 1.66667 h;

Steps:

4.1.1. Benzyl 3-O-benzyl-4,6-O-benzylidiene-2-O-[3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-β-d-glucopyranosyl]-α-d-mannopyranoside (7)

To a mixture of 5 (255 mg, 0.57 mmol), silver trifluoromethanesulfonate (263 mg, 1.02 mmol), and collidine (135 μL, 1.02 mmol) in nitromethane (1 mL) was added a nitromethane (2 mL) solution of 6 (426 mg, 0.86 mmol) at -20 °C. The reaction mixture was stirred at -20 °C for 10 min and room temperature for 1.5 h before being filtered through Celite and concentrated in vacuo. The residue was purified by silica gel chromatography (toluene/diethyl ether = 3:1) to afford 7 (280 mg, 57%). ¹H NMR (300 MHz, CDCl₃) δ: 1.93, 2.08 and 2.09 (each s, 3H), 3.20 (t, J = 10.1 Hz, 1H), 3.52-3.65 (m, 1H), 3.71-3.76 (m, 1H), 3.88-3.96 (m, 3H), 4.15-4.17 (m, 1H), 4.25 (d of ABd, J_AB = 12.2 Hz, J = 2.3 Hz, 1H), 4.33 (ABd, J_AB = 11.7 Hz, 1H), 4.34 (d of ABd, J_AB = 12.2 Hz, J = 4.7 Hz, 1H), 4.52 (ABd, J_AB = 11.7 Hz, 1H), 4.53 (dd, J = 10.8 and 8.4 Hz, 1H), 4.64 (s, 1H), 4.67-4.76 (m, 2H), 5.22 (t, J = 9.6 Hz, 1H), 5.44 (d, J = 8.4 Hz, 1H), 5.50 (s, 1H), 5.92 (dd, J = 10.7 and 9.1 Hz, 1H), 7.20-7.48 (m, 15H), 7.77-7.82 (m, 2H), 7.88-7.91 (m, 2H); MS FAB(+) m/z 866 [(M+H)⁺, 26]; HR-MS calcd for C₄₇H₄₇NO₁₅Na [(M+Na)⁺] 888.2843, found: 888.2845.

References:

Mukai, Takahiro;Hagimori, Masayori;Arimitsu, Kenji;Katoh, Takahiro;Ukon, Misa;Kajimoto, Tetsuya;Kimura, Hiroyuki;Magata, Yasuhiro;Miyoshi, Eiji;Taniguchi, Naoyuki;Node, Manabu;Saji, Hideo [Bioorganic and Medicinal Chemistry,2011,vol. 19,# 14,p. 4312 - 4321] Location in patent:experimental part