By treatment with Br2CF2 and Ph3P, 4 unfunctionalized olefins, 4 enol ethers and 1 bis-enol ether were converted to gem-difluorocyclopropanes. Thus, RCH:CHOPr (R = H, Me) gave difluorocyclopanes I in 73 and 83% yield, resp. 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 a moderate excess of reagents. [on SciFinder (R)]
Title
gem-Difluorocyclopropanes: an improved method for their preparation
Published in
Tetrahedron
Volume
46
Issue
15
Pages
5213-5221
Date
1990
ISSN
0040-4020
Note
CAN 114:42086
24-2
Alicyclic Compounds
Inst. Chim. Org.,Univ. Lausanne,Lausanne,Switz.
Journal
written in English.
107-21-1 (1,2-Ethanediol) Role: RCT (Reactant), RACT (Reactant or reagent) (allylation of, with allyl bromide); 110-83-8 (Cyclohexene); 110-87-2; 111-34-2; 116-11-0; 627-97-4; 4050-45-7; 7688-21-3 Role: RCT (Reactant), RACT (Reactant or reagent) (cyclopropanation of, with dibromodifluoromethane); 75-61-6 (Dibromodifluoromethane) Role: RCT (Reactant), RACT (Reactant or reagent) (cyclopropanation reaction of, with butoxypropene, alkenes and enols, difluorocyclopropanes from); 75-71-8 (Dichlorodifluoromethane); 1514-87-0 (Methyl chlorodifluoroacetate); 1895-39-2 (Sodium chlorodifluoroacetate); 58201-66-4 Role: RCT (Reactant), RACT (Reactant or reagent) (cyclopropanation reaction of, with butoxypropene, difluorocyclopropane from); 3739-64-8 (Allyl butyl ether) Role: RCT (Reactant), RACT (Reactant or reagent) (isomerization of); 16850-55-8P ((Z)-1-Butoxypropene) Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. and cyclopropanation of, with difluorocarbene); 823-70-1P; 59164-23-7P; 131262-44-7P; 131262-45-8P; 131262-47-0P; 131262-48-1P; 131262-51-6P; 131347-60-9P; 133744-87-3P; 133744-88-4P; 133744-89-5P; 133744-90-8P Role: SPN (Synthetic preparation), PREP (Preparation) (prepn. of); 131262-50-5P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn., dimerization, and cyclopropanation of, with dibromodifluoromethane)
Record creation date
2006-03-03
