OsO4NaIO4氧化合成醛
OsO4/NaIO4被稱為Lemieux-Johnson試劑,此反應也被稱為Lemieux-Johnson氧化。
與臭氧化法相比,
OsO4/NaIO4
是一種溫和的
烯烴氧化開裂法,在天然產物合成中很有用。烯烴先與
OsO4
反應生成鋨酸酯,再用過碘酸鈉氧化,發生開裂,在生成羰基化合物的同時,
OsO4
再生,所以
OsO4
用催化量即可。當生成的醛易於分子內縮合時,反應最好在兩相系統中進行。
To asolution of
1
(1。8 mg) in THF(1 mL) was added
OsO4
(excess) and then a solutionof NaIO4, (excess) in H2O (1 mL)。 After a period of 1 hr,H2O (5 mL) was added andthe aq。 solution was extracted with three 5ml portions of CHCl3。 Thecombined CHCl3 layers were dried over Na2SO4,and concentrated to give a residue, which was separated by preparation TLC (SiO2,5% MeOH-CHCl3)。 Compounds
2
and
3
wereobtained。
【
Tetrahedron,
41; 6; 1985;1007-1018
】
。
Criegee臭氧化反應