77524-09-5Relevant articles and documents
Photochemically Induced Mercuric Oxide-Iodine Oxidation of Some Unsaturated Steroid Compounds
Dabovic, Milan,Bjelakovic, Mira,Andrejevic, Vladimir,Lorenc, Ljubinka,Mihailovic, Mihailo Lj.
, p. 1833 - 1846 (2007/10/02)
Photochemically induced HgO/I2 oxidation of cholest-5-en-3α-ol (6) and cholest-5-en-3β-ol (7) afforded (Scheme 3) products arising from the corresponding alkoxy radicals (12, 13 and 14a,b) and from attack of the I2O intermediate at the olefinic double bond (epoxides 15a and 16a,b, respectively).With cholest-5-ene-1α,3β-diol 3-acetate (8) and cholest-7-ene-3β,5α-diol 3-acetate (9) the HgO/I2 oxidation led to unresolvable complex mixtures (Scheme 5).With the same reagent cholest-5-en-3α-ol acetate (10) and cholest-5-en-3β-ol acetate (11) underwent exclusively attack by I2O, to give epoxides 20a,b, iodohydrin 21, and rearranged products 19 and 22 (scheme 7), in the case of 10, and predominantly epoxides 23a,b (scheme 8), in the case of 11.
Photo-induced Transformations. Part 51. Photo- and Thermally-induced Rearrandements of Hypoiodites of Steroidal Homoallyl Alcohols. The Formation of Some Oxygen Heterocycles via Photo- and Thermally-induced Rearrangements of 3-Hydroxy-Δ5-steroid Hypoiodites in the Presence of ...
Suginome, Hiroshi,Furusaki, Akio,Kato, Kimitoshi,Maeda, Norio,Yonebayashi, Fumihiko
, p. 236 - 250 (2007/10/02)
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 hypoiodite was induced thermally at 55-60 deg C, only the 6β-isomer, accompanied by cholest-5-en-3α-yl A-homo-4-oxacholest-5-en-3α-yl ether (20) and A-homo-4-oxacholest-5-en-3α-ol (21), is formed.Catalytic hydrogenolysis of iodo-epoxide (3) or (4) gave 3α,5-epoxy-A-homo-4-oxa-5β-cholestane (16) which was transformed into 2-acetyl-5-acetoxymethyl-4-oxa-5β-cholest-2-ene (29) upon treatment with boron trifluoride-ether-acetic anhydride in benzene.In contrast, the newly synthesized hypoiodite of 3α,4,4-trimethylcholest-5-en-3β-ol, in benzene containing mercury (II) oxide and iodine, gave 2-acetyl-3-oxacholest-5-enes (26) and (27) together with 3α,5α-epoxy-A-homo-4-oxasteroids (24) and (25) on irradiation or thermolysis.The formation of the products (26) and (27) indicates the intervention of a common oxyl radical (E) in the rearrangements of 3-hydroxy-Δ5-steroid hypoiodites to products (3), (4), (24), (25), (26), and (27).The pathways of the rearrangements and the stereoselectivity of the reactions are discussed.