Methyl iodide → 1-o-Oleyl-2-o-methyl-3-o-trityl glycerol

Beteiligte Stoffe

Reaktionsschritte

To a mixture of NaH (4.8 g, 120 mmol) and NaI (0.2 g) in dry DMF (20 mL) was added solketal (5.0 mL, 40 mmol) dropwise over a 30 min period. Once the effervescence had stopped, oleyl tosylate (34) (16.9 g, 40 mmol) was added and the reaction mixture was left for 3 days at 50° C. Then, H2O (10 mL) was added and the mixture was extracted with diethyl ether (2×100 mL), the combined organic phases were dried (MgSO4) and evaporated to dryness. The residue was taken up in THF (150 mL), 2M HCl was added until the solution turned turbid and the reaction was left to stir for 16 h. The mixture was concentrated and subjected to silica-gel column chromatography [eluent: ethyl acetate/hexane, 50/50, v/v] to give 1-O-oleyl-rac-glycerol (32) as an oil. Diol 32 (2.0 g, 5.97 mmol) was added dropwise to a solution of trityl chloride (1.66 g, 6.0 mmol) in anhydrous pyridine (10 mL). The reaction was left to stir for 16 h after which the solvent was removed by co-evaporation with toluene (2×5 mL). Then, part of the residue (1.0 g, 1.7 mmol) was added dropwise to a suspension of NaH (0.14 g, 3.4 mmol) in THF (50 mL), followed by the addition of MeI (0.22 mL, 3.4 mmol). After 16 h, TLC analysis showed that the reaction had gone to completion and H2O (5 mL) was added followed by concentration of the reaction mixture. The residue was partitioned between H2O (20 mL) and diethyl ether (100 mL), the organic extract was washed with sat. NaHCO3 (10 mL), dried (MgSO4) and concentrated to give 1-O-oleyl-2-O-methyl-3-O-trityl glycerol (33) as an oil.

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