| abstract |
PURPOSE: To obtain the titled compound useful as an intermediate for active vitamin D 3 or such, industrially advantageously, by treating a cholesterol-24- sulfonate with a base. n CONSTITUTION: 1mol 24,25-dihydroxycholesterol shown by formula I (R 1 is H or protecting group; R 2 is H, OH or protected OH) (e.g., 3β- benzoyloxycholest-5-ene-24,25-diol, etc.) is reacted with preferably 0.5W10mol organic sulfonyl chloride (e.g. methanesulfonyl chloride, etc.) shown by the formula R 3 -SO 2 Cl (R 3 is lower alkyl or aryl) in a solvent such as pyridine, etc., at -20W100°C for 5minW24hr to form a cholesterol-24-sulfonate shown by formula II. Then this compound is treated with a base (e.g., NaHCO 3 , etc.) to give the aimed compound (e.g. 3β-benzoyloxycholest-5-ene-25-ol-24-mesylate, etc.) shown by formula III. n COPYRIGHT: (C)1987,JPO&Japio |