Olefination of α-Hydroxy or α-Aminoaldehyde Derivatives via Reaction of Their Arylsulfonylhydrazones with Sulfonyl Anions
作者:Jerzy Wicha、Andrzej Zarecki
DOI:10.1021/jo0499118
日期:2004.8.1
Reaction of tosylhydrazones of O-substituted a-hydroxy or N-substituted a-amino aldehydes (2, 7, 11, 15, 17, and 20) with selected alpha-magnesio alkyl phenyl sulfones afforded the respective derivatives of allylic alcohols or allylic amines. 2,3-O-Isopropylidene-D-glyceraldehyde (1) was transformed into its tosylhydrazone (2) and then olefins 4a with retention of optical purity.
Unexpected Differences in the α-Halogenation and Related Reactivity of Sulfones with Perhaloalkanes in KOH−<i>t</i>-BuOH
作者:Cal Y. Meyers、Roch Chan-Yu-King、Duy H. Hua、Vera M. Kolb、Walter S. Matthews、Thomas E. Parady、Toyokazu Horii、Paul B. Sandrock、Yuqing Hou、Songwen Xie
DOI:10.1021/jo025781w
日期:2003.1.1
variety of other important results. 4-Hydroxyphenyl isopropyl sulfone (6) is unreactive with either CCl4 or CBrCl3 in KOH-t-BuOH, its phenoxideanion strongly reducing the electronegativity of the sulfonyl group, thereby inhibiting alpha-anion formation. This effect is reversed by the electron-withdrawing influence of two alpha-phenyls, so that benzhydryl 4-hydroxyphenyl sulfone (8) is readily alpha-halogenated