Titanium Tetrachloride Induced Fries Rearrangement: A New Route to Disubstituted 2′- Hydroxypropiophenones
作者:Robert Martin、Pierre Demerseman
DOI:10.1055/s-1989-27134
日期:——
Fries rearrangement of some dialkylphenyl propionates with titanium tetrachloride proves to be a convenient route to hindered dialkyl 2′-hydroxypropiophenones. The sequential use of soft titanium tetrachloride to perform the Fries rearrangement followed by hard aluminum chloride to achieve the elimination of a protecting tert-butyl group allows the synthesis of some previously unknown 3′,6′- and 5′,6′-dialkyl-2-hydroxypropiophenones.
某些二烷基苯丙酸酯与四氯化钛的Fries重排证明是一条合成受阻的二烷基2′-羟基丙酰苯酮的便捷途径。先使用较温和的四氯化钛进行Fries重排,然后再用较强的氯化铝去除保护性叔丁基基团,这样可以合成一些以前未知的3′,6′-和5′,6′-二烷基-2-羟基丙酰苯酮。