| 摘要 |
PROBLEM TO BE SOLVED: To efficiently deprotect the subject derivative by adding 4phenyl 1,2,4-triazoline-3,5-dione to a 5,7-diene compound of steroid to give a derivative and treating the derivative with diazabicycloundecene. SOLUTION: 4-Phenyl-1,2,4-triazoline-3,5-dione is added to a 5,7-diene compound (e.g. 1α,3β-diacetoxy-5,7-cholestadiene) of steroid so that an adduct of steroid-(4-phenyl-1,2,4-triazoline-3,5-dione) shown by the formula (R<1> is H, acetyl, etc.; R<2> is H, OH or acetoxy; R<2> is a hydrocarbon chain; Ph is phenyl), etc., in which the 5,7-diene is protected is treated with diazabicycloundecene to eliminate 4-phenyl-1,2,4-triazoline-3,5-dione. Consequently, the 5,7-diene compound of steroid is efficiently deprotected and regenerated.
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