Compound 11

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Synthetic procedure: See article for the definitive version of this procedure and for full experimental details.

TBAF (1 M in THF, 45 μL, 45 μmol) was added at 50 °C to a solution of Glucosylceramide 10 (45.1 mg, 30 μmol) in THF (0.9 mL). The solution turned immediately from colorless to yellow. The mixture was stirred for 40 min and then partitioned between EtOAc and H₂O. The organic layer was washed with water two times. The combined aqueous layers were extracted with EtOAc two times and the combined organic layers were washed with brine, dried over MgSO₄, and the solvent was evaporated. Purification of the residue by column chromatography on silica gel (isohexane/EtOAc 1:0 to 4:1) afforded (R)-2-(benzyloxy)-N-((2S,3S,4R)-3,4-bisbenzyloxy-1-((O²,O³,O⁴-tribenzyl-β-D-glucopyranosyl)oxy)-15-methylhexadecan-2-yl)docosanamide (34.0 mg, 25 μmol, 84%).

A round-bottom flask filled with (R)-2-(benzyloxy)-N-((2S,3S,4R)-3,4-bisbenzyloxy-1-((O²,O³,O⁴-tribenzyl-β-D-glucopyranosyl)oxy)-15-methylhexadecan-2-yl)docosanamide (30.8 mg, 23 μmol) and Pd/C (10%, 3.7 mg) was evacuated and set under H₂ (balloon). EtOAc (0.4 mL) and EtOH (0.8 mL) were added and the mixture was stirred at room temperature for 17 h. The solvent was evaporated and the residue was purified by column chromatography on silica gel (CH₂Cl₂/isohexane/MeOH 90:10:2 to 90:5:10) to afford the glucosylceramide d17iso-Glc-Cer (11) (16.7 mg, 21 μmol, 91%). ¹H NMR (600 MHz, CD₃OD (3.32)): (ppm) = 0.89 (d, J = 6.6 Hz, 6 H (2 H₃-16^LCB)), 0.91 (t, J = 6.9 Hz, 3 H (H₃-22^FA)), 1.17–1.21 (m, 2 H (H₂-14^LCB)), 1.30 (br s, 51 H), 1.40–1.46 (m, 2 H), 1.54 (non, J = 6.6 Hz, 1 H (H-15^LCB)), 1.50–1.66 (m, 2 H), 1.73–1.78 (m, 1 H), 3.179 (dd, J = 9.2, 7.8 Hz, 1 H (H-2^Glc)), 3.28–3.29 (m, 2 H (H-5^Glc, H-2^FA)), 3.35–3.38 (m, 1 H (H-3^Glc)), 3.53 (ddd, J = 9.7, 5.9, 2.5 Hz, 1 H (H-4^LCB)), 3.63 (t, J = 6.1 Hz, 1 H (H-3^LCB)), 3.66–3.69 (m, 1 H (H_A-6^Glc)), 3.81 (dd, J_AB = 10.5 Hz, J =3.8 Hz, 1 H (H_A-1^LCB)), 3.88 (dd, J_AB = 12.0 Hz, J = 1.6 Hz, 1 H (H_B-6^Glc)), 4.02 (dd, J = 7.6; 3.9 Hz, 1 H (H-4^Glc)), 4.07 (dd, J_AB = 10.4 Hz, J = 6.2 Hz, 1 H (H_B-1^LCB)), 4.26 (td, J = 6.3, 3.8 Hz, 1 H (H-2^LCB)), 4.29 (d, J = 7.8 Hz, 1 H (H-1^Glc)). ¹³C NMR (HSQC-projection) (151 MHz, CD₃OD (49.0)): (ppm) = 14.4 (CH₃ (C-22^FA)), 23.1 (2 CH₃ (C-16^LCB)), 23.8 (CH₂), 26.2 (CH₂), 27.0 (CH₂), 27.2 (CH₂), 28.8 (CH₂), 29.3 (CH (C-15^LCB)), 30–34 (20 CH₂), 33.3 (CH₂), 35.4 (CH₂), 35.9 (CH₂), 40.3 (CH₂ (C-14^LCB)), 51.8 (CH (C-2^LCB)), 62.9 (CH₂ (C-6^Glc)), 70.1 (CH₂ (C-1^LCB)), 71.6 (CH (C-5^Glc)), 73.1 (2 CH (C-4^Glc, C-4^LCB)), 75.1 (CH (C-2^Glc)), 75.6 (CH (C-3^LCB)), 78.0 (CH (C-3^Glc)), 78.1 (CH (C-2^FA)), 105.0 (CH (C-1^Glc)). ESI-MS: m/z (10 V) = 827.1 [M+Na]⁺. [α]_D²⁰ = +11 (c = 0.06, MeOH). HRMS: C₄₅H₈₉NO₁₀. [M+H]⁺: calcd.: 804.6559, found: 804.6572.