gem-Difluorocyclopropanes: an improved method for their preparation

Y Bessard, U Müller, M Schlosser

Index: Bessard, Yves; Mueller, Ulrich; Schlosser, Manfred Tetrahedron, 1990 , vol. 46, # 15 p. 5213 - 5221

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Citation Number: 35

Abstract

By treatment with dibromodifluoromethane and triphenylphosphine, four unfunctionalized olefins, four enethers and one bis-enether were converted to the gem-difluorocyclopropanes 1-9. The yields were considerably increased and isomerizations at the double bonds were avoided if the reactions were carried out in the presence of a macrocyclic polyether such as “18-crown-6” and if, in addition, the reagents were employed in moderate excess.