1999 hydroxylation, hydroboration, phosphorylation, silylation

hydroxylation, hydroboration, phosphorylation, silylationO 0275

48 - 076A Novel Allylic Hydroxylation of Sterically Hindered Olefins by Fe–Porphyrin-Catalyzed mCPBA Oxidation. — Triterpenes such as (I)bearing a sterically hindered olefin readily undergo a novel allylic hydroxylationby MCPBA in the presence of iron(III) tetrakis(pentafluorophenyl)porphyrinchloride as catalyst. Sterically unhindered olefins [cf. (III), (V)] are converted toepoxides under these conditions. — (KONOIKE, TOSHIRO; ARAKI, YOSHI-TAKA; KANDA, YASUHIKO; Tetrahedron Lett. 40 (1999) 38, 6971-6974;Shionogi Res. Lab., Shionogi Co., Ltd., Amagasaki, Hyogo 660, Japan; EN)

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