| 摘要 |
<p>PURPOSE:To enable to selectively prepare a compound useful as a synthetic intermediate for a therapeutic agent for calcium metabolism-deicient diseases in a good yield by irradiating a 1alpha-hydroxytachysterol derivative with UV laser rays having a specific wavelength. CONSTITUTION:A compound of formula I [R<1>, R<2> are H, OH-protecting group; R<3>, R<4> are lower alkyl, or form ethylene together; X is O, methylene, vinylene; Y is H, methyl, OR<5>; Z is H, OR<6> (R<5>, R<6> are H. OH-protecting group); (n) is 0-4] is irradiated with UV later rays having a wavelength of 280-400nm. The compound of formula I is irradiated with a UV laser rays-generating laser such as krypton fluoride excimer laser to prepare the objective compound.</p> |
