NEW MATERIAL:A 25-hydroxy-24-oxovitamin D3 shown by the formula I (R1 and R3 are H or OH-protecting group; R2 is H, OH, or OH-protecting group) and its OH-protected derivative.
EXAMPLE: 25-Hydroxy-24-oxovitamin D3.
USE: A vitamin D3 like pharmacologically active agent and a synthetic intermediate for other active type vitamin D3.
PROCESS: A compound shown by the formula II is irradiated by ultraviolet light with wavelength about 200W360nm, preferably 260W310nm to give a compound shown by the formula III. The reaction is carried out at -20W120°C, preferably -10W 50°C. The compound shown by the formula III is isomerized by thermal energy at 20W120°C, preferably at 40W100°C. Both the reactions are preferably carried out in an inert organic solvent, e.g., hexane, etc.
ISHIMARU KENJI
TAKESHITA TOORU
TSURUTA HIDEKI
