INSERTION OF OXYGEN ATOM IN STEROID FRAMEWORKS–A NEW METHOD OF TRANSFORMATION OF HYDROXYSTEROID INTO OXASTEROID
作者:Hiroshi Suginome、Shinji Yamada
DOI:10.1246/cl.1982.1233
日期:1982.8.5
A two-step transformation of saturated hydroxysteroids into oxasteroids is described; the reaction involves photo-reaction of the hypoiodites of the hydroxysteroids generated with mercury(II) oxide and iodine to give isomeric formyl esters [e.g., 2 and 3], which are cyclized to oxasteroids [e.g.,4 and 5] with sodium borohydride.
Photoinduced transformations. Part 73. Transformations of five- (and six-) membered cyclic alcohols into five- (and six-) membered cyclic ethers - a new method of a two-step transformation of hydroxy steroids into oxasteroids
作者:Hiroshi Suginome、Shinji Yamada
DOI:10.1021/jo00194a015
日期:1984.10
Synthesis of Some Five- and Six-Membered Oxasteroids of Cholestane Series by Ring Contraction and the Mass Spectrometric Fragmentations of Oxasteroids
作者:Hiroshi Suginome、Shinji Yamada
DOI:10.1246/bcsj.60.2453
日期:1987.7
Synthesis of several new five- and six-membered oxasteroids of the cholestane series by the ring contraction of those oxasteroids whose oxygen-containing ring is larger by one member has been achieved. Ring contraction utilizes a series of reactions recently developed by us for the transformation of cyclic ketones into cyclic ethers; it involves a regioselective β-scission of the alkoxyl radical generated