Photo-induced transformations. Part 51. Photo- and thermally-induced rearrangements of hypoiodites of steroidal homoallyl alcohols. The formation of some oxygen heterocycles via photo- and thermally-induced rearrangements of 3-hydroxy-Δ<sup>5</sup>-steroid hypoiodites in the presence of mercury(<scp>II</scp>) oxide and iodine
作者:Hiroshi Suginome、Akio Furusaki、Kimitoshi Kato、Norio Maeda、Fumihiko Yonebayashi
DOI:10.1039/p19810000236
日期:——
Hypoiodites of cholesterol and epicholesterol in benzene containing mercury(II) oxide and iodine underwent photo-induced rearrangement to give 3α,5-epoxy-6β- and -6α-iodo-A-homo-4-oxa-5α-cholestanes (3) and (4), together with 3-formyloxy-2-iodo-A-nor-2,3-secocholest-5-ene (2). Stereochemistry of the epoxide (3) was established by an X-ray crystallographic analysis. When the reaction of cholesterol
在苯含汞(胆固醇和epicholesterol的次碘酸盐II)氧化物和碘后行光致重排,得到3α,5-环氧- 6β-和-6α碘-阿-homo -4-氧杂- 5α-胆甾烷(3) (4)与3-甲酰氧基-2-碘-A -nor-2,3-secocholest-5-烯(2)一起。通过X射线晶体学分析确定了环氧化物(3)的立体化学。当胆固醇次碘酸根的反应在55-60℃下,只有6β异构体热引起的,伴随着胆甾-5-烯3α基甲-homo -4- oxacholest -5-烯3α基醚( 20),形成了-homo-4-oxacholest-5-en-3α-ol(21)。碘代环氧化合物(3)或(4)的催化氢解反应得到3α,5-环氧-A-homo-4-oxa-5β-胆甾烷(16)经三氟化硼-乙醚-乙酸酐处理后转化为2-乙酰基-5-乙酰氧基甲基-4-oxa-5β-胆甾-2-烯(29)苯。