[2,3]-Wittig Rearrangements of Difluoroallylic Ethers. A Facile Entry to Highly Functionalized Molecules Containing a CF<sub>2</sub> Group
作者:Sunita T. Patel、Jonathan M. Percy、Robin D. Wilkes
DOI:10.1021/jo951516h
日期:1996.1.1
Readily prepared primary, secondary, and tertiary difluoroallylic alcohols, derived from commercially available and inexpensive 2,2,2-trifluoroethanol, have been transformed into a range of difluoroallylic methyl ethers containing appropriate carbanion-stabilizing substituents. The [2,3]-Wittig rearrangements of these difluoroallylic ethers have been achieved cleanly, using lithium diisopropylamide in tetrahydrofuran at -30 degrees C, in excellent (secondary ether substrates) to good (primary and tertiary ether substrates) yields. Consequently, the approach allows convenient and rapid access to products containing a mid-chain CF2 group and with a useful level of functionality.