HCID 13882746, compound → L-Ascorbic Acid

Participants

Reaction Steps

251 mg of DIAD (1.25 mmol) is added to a solution of triphenylphosphine (326 mg, 1.25 mmol) in anhydrous THF (2 mL) cooled to −15° C. After 15 minutes, a white precipitate of Mitsunobu betaine is formed. Stirring is continued for 10 minutes, then a solution of 5-(2,2-dimethyl-[1,3]dioxolan-4-yl)-3-hydroxy-4-methoxymethoxy-5H-furan-2-one (246 mg, 1.19 mmol) in THF (2 mL) is added followed by 400 mg of 1,1′,2-trisnorsqualenol (1.04 mmol) in 2 mL of THF. The mixture is stirred at −15° C. for 30 min, then the reaction mixture is left to return to room temperature, continuing stirring for an additional time of 2 h. The reaction mixture is then concentrated, the residue is taken up in 20 ml of ethyl acetate and the organic phase is washed successively with a saturated solution of sodium bicarbonate (3 ml) and then with saturated NaCl solution (3 ml). The organic phases are dried over magnesium sulfate and concentrated under reduced pressure. The crude mixture is purified by silica-gel flash chromatography, eluting with cyclohexane/EtOAc mixture (1:1) to give fully protected squalenyl ascorbic acid in the form of a colorless oil (438 mg, 67%).

Provenance & Evidence