High stereoselective preparation of O-protected 2-trifluoromethyl 3-bromoallylic alcohols from 1,1-dibromo-1-alkenes.
A highly stereoselective lithium-bromine exchange reaction of 2-trifluoromethyl-3,3-dibromoallylic alcohols is described. (E)- and (Z)-2-trifluoro-3-bromoallylic alcohols were obtained in THF and hexane, respectively. The lithium carbenoid intermediate was stable even at -40 degrees C and could be trapped by various electrophiles to afford functionalized 2-trifluoromethyl-3-bromoallylic alcohols. [reaction: see text]
Li
Youhua
Y
Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, China.
Lu
Long
L
Zhao
Xiaoming
X