Hydrogenolytic cleavage of methyl 4,6-O-(4-methoxybenzylidene)-α-D-glucopyranoside with LiAlH4-AlCl3

Chiral Cyclopentane-Based Mimics of d-myo-Inositol 1,4,5-Trisphosphate from d-Glucose

“…The 1 H NMR spectrum of 12 displayed a deshielded triplet at 5.28 ppm, corresponding to the position 4 methine; the position 6 methylene protons of 13 were deshielded to 4.46−4.97 ppm. The selectivity of p -methoxybenzylidene cleavage in this case was much poorer than that reported for the corresponding 2,3-di- O -benzyl glucoside; however, exclusive formation of 11 was observed on treatment of 9 with LiAlH 4 −AlCl 3 in refluxing THF …”

“…1:1.7. The structures of 10 and 11 were established by comparison of the chemical shifts of their position 6 carbon atoms, as observed in the 13 C NMR spectra in CDCl 3 . The C-6 of 10 resonates at lower field (69.2 ppm) than that of 11 (61.8 ppm) due to the R-effect of alkylation.…”

“…The selectivity of p-methoxybenzylidene cleavage in this case was much poorer than that reported for the corresponding 2,3-di-O-benzyl glucoside; 11 however, exclusive formation of 11 was observed on treatment of 9 with LiAlH 4 -AlCl 3 in refluxing THF. 13 Aldehyde 14 was smoothly prepared by Swern oxidation 14 of 11. After column chromatography, the IR spectrum indicated absorption at 3400-3650 cm -1 , corresponding to OH stretching, in addition to the expected absorption at 1745 cm -1 , corresponding to CdO stretching.…”

“…The combined organic extracts were washed with H2O (2 × 100 mL), dried (MgSO4), filtered, and concentrated to give crude 9 (11.8 g). Crystallization from EtOH gave pure 9 (10.9 g, 87%): TLC (hexane/EtOAc 4:6) Rf ) 0.60; mp 144-145 °C; [R]D ) -30.0 (c 1.2, CHCl3); 1 H NMR (CDCl3, 270 MHz) δ 3.40 (s, 3 H, OCH3), 3.50-3.59 (m, 2 H, C-2-H, C-4-H), 3.64-3.98 (m, 8 H, C-5-H, C-6-Hax, 2 × ArOCH3), 4.02 (t, J ) 9.1Hz, 1 H, C-3-H), 4.39 (dd, 3 J6-Heq,H-5 ) 4.3Hz, 2 J6-Heq,6-Hax ) 9.8Hz, 1 H, C-6-Heq), 4.57 (d, J ) 3.7Hz, 1 H, C-1-H), 4.67-4.88 (m, 4 H, 2 × ArCH2O AB systems), 5.50 (s, 1 H, C-7-H), 6.82-6.92 (m, 4 H, 2 × C-3-H and C-5-H of p-substituted rings), 7.25-7.43 (m, 9 H, aromatic CH); 13 11). (a) A solution, kept at 0 °C, of trimethylsilyl chloride (12.5 mL, 98.4 mmol) in dry acetonitrile (15 mL) was added dropwise under N2 to a vigorously stirred mixture of 9 (8.6 g, 16.4 mmol), sodium cyanoborohydride (6.2 g, 98.4 mmol), 3 Å molecular sieves, and dry acetonitrile (150 mL) at 0 °C.…”

On the Properties of Benzyl Ether Bonds in the Lignin-Saccharidic Complex Isolated from Spruce

“…Methyl 4-O-anisyl-a-D-glucopyranoside and methyl 4-Ovanillyl-a-D-glucopyranoside were prepared by hydrogenolytic cleavage of the corresponding acetals with LiAlH 4 -A1C1 3 (Joniak et al 1978).…”