Deoxygenation of Steroidal Ring-D 16,17-Ketols with Timethylsilyl Iodide.
作者:Masao NAGAOKA、Etsuko NAGASAWA、Mitsuteru NUMAZAWA
DOI:10.1248/cpb.46.1857
日期:——
Reaction of various steroidal 16, 17-ketols, 16α-hydroxy-17-ketones 1-3, and 15, 16β-hydroxy-17-ketone 4, and 17β-hydroxy-16-ketones 5-7, and 17, along with methyl ethers of 16α- and 17β-ketols, 1 and 5, with an excess of trimethylsilyl iodide (TMSI) or with HI in CHCl3, produced the deoxygenated products, a mixture of the corresponding 17-and 16-ketones, in low to quantitative yields, in which the 17-ketone was the major product in each case. When the 16β-deuterated 16α-ketol 3 and the 17α-deuterated 17β-ketol 7 were reached with TMSI for a brief period (15 min), the deuterium content at C-16β and C-17α of the recovered steroids 3 and 7 was reduced by 17 and 35%, respectively. The present results indicate that the deoxygenation proceeds not only through a direct iodination pathway producing α-iodoketone but also through other reaction pathways.
各种类固醇16,17-酮醇、16α-羟基-17-酮1-3、15,16-羟基-17-酮4,以及17β-羟基-16-酮5-7和17的反应,以及16α-和17β-酮醇的甲醚1和5与过量的三甲基硅基碘(TMSI)或HI在氯仿中的反应,产生脱氧产物,即相应的17-和16-酮的混合物,产量从低到定量不等,其中17-酮是每种情况下的主要产物。当16β-氘化的16α-酮醇3和17α-氘化的17β-酮醇7与TMSI短暂接触(15分钟),恢复的类固醇3和7中的C-16β和C-17α位的氘含量分别减少了17%和35%。当前结果表明,脱氧过程不仅通过直接碘化途径生成α-碘酮,还通过其他反应途径。