The generation of difluoroenolates from trifluoroethanol and reproducible syntheses of α,α-difluoro-β-hydroxy ketones
作者:Andrew S. Balnaves、Thomas Gelbrich、Michael B. Hursthouse、Mark E. Light、Michael J. Palmer、Jonathan M. Percy
DOI:10.1039/a902966d
日期:——
Metallated difluoroenol carbamate 1 reacted with aldehydes and ketones in the presence of highly oxophilic Lewis acid boron trifluorideâethyl ether; the Lewis acid attenuated the transacylation reaction to the corresponding enolates so that allylic alcohols could be isolated. Treatment of the allylic alcohols with strong base afforded difluoroenolates which could be trapped cleanly in aldol reactions.
金属化的二氟烯醇氨基甲酸酯1在高度亲氧的路易斯酸氟化硼-乙醚存在下与醛和酮反应;该路易斯酸抑制了转酰化反应,转变为相应的烯醇化合物,从而可以分离出烯丙醇。用强碱处理这些烯丙醇可得到二氟烯醇化合物,这些化合物能够在羟醛反应中被有效捕获。