Diiodosilane. 4.<sup>1</sup>Direct Reduction of Ketals and Acetals in the Presence of Unprotected Carbonyls. A Case of Inverted Chemoselectivity
作者:E. Keinan、M. Sahai、R. Shvily
DOI:10.1055/s-1991-26533
日期:——
Ketals and acetals are selectively reduced by diiodosilane to iodoalkanes in preference to ketones and aldehydes. This inversion of the normal order of reactivity of the "protected" and "unprotected" carbonyls allows partial reduction of polycarbonyl compounds with unusual regio- and chemoselectivity. Thus, 8,8-(ethylenedioxy)octan-2-one, 7,7-(ethylenedioxy)octanal, 3,3-(ethylenedioxy)-androstan-17-one and 3,3-(ethylenedioxy) pregnane-11,20-dione are converted to the corresponding iodo compounds.
酮和醛可被二碘硅烷选择性地还原成碘烷。这种颠倒 "受保护 "和 "未受保护 "羰基的正常反应顺序的做法,可以部分还原多羰基化合物,并具有不同寻常的区域和化学选择性。 因此,8,8-(亚乙二氧基)辛烷-2-酮、7,7-(亚乙二氧基)辛醛、3,3-(亚乙二氧基)-雄甾烷-17-酮和 3,3-(亚乙二氧基)孕烷-11,20-二酮被转化为相应的碘化合物。