Synthesis of C16–C27-fragments of bryostatins modified by 20,20-difluorination
作者:Paul R. Mears、Eric J. Thomas
DOI:10.1016/j.tetlet.2015.05.007
日期:2015.6
2-Hydroxytetrahydropyrans corresponding to the C16-C27 fragment of bryostatins which have been difluorinated at C20 (bryostatin numbering) have been synthesised. The fluorine substituents were introduced by difluoroallylation. An (E)-selective Wittig reaction using a stabilised ylide provided the required methoxycarbonylmethylene substituent with excellent stereoselectivity. (C) 2015 Elsevier Ltd. All rights reserved.
Copper-free defluorinative alkylation of allylic difluorides through Lewis acid-mediated C–F bond activation
The reactions of difluorohomoallyl alcohols with trialkylaluminiums smoothly proceeded in CH2Cl2 at room temperature to give (Z)-fluoro-olefin products in excellent yields. On the basis of this chemistry, fluoro-olefinic dipeptide isostere of norvalinyl glycine was synthesized in stereoselective manner. (C) 2011 Elsevier Ltd. All rights reserved.