An expedient method for the prepn. of diastereomerically and, by extension, even enantiomerically pure vicinal difluoroalkanes is described. The two fluorine atoms are introduced in two consecutive steps: ring opening of an oxirane by addn. of hydrogen fluoride and subsequent treatment of the resulting hydroxy fluoride with diethylaminosulfur trifluorides. Thus, sep. treatment of (E)- and (Z)-RCH:CHR [R = (CH2)4Me] via epoxidn., HF addn, and fluorination, gave dl- or meso-RCHFCHFR, resp. [on SciFinder (R)]
Titre
A stereocontrolled access to vicinal difluoroalkanes
Publié dans
Tetrahedron
Volume
44
Numéro
10
Pages
2875-2881
Date
1988
ISSN
0040-4020
Note
CAN 110:94451
23-3
Aliphatic Compounds
Inst. Chim. Org.,Univ. Lausanne,Lausanne,Switz.
Journal
written in English.
130888-52-7 Role: RCT (Reactant), RACT (Reactant or reagent) (fluorination of, with diethylaminosulfur trifluoride); 7782-41-4 Role: RCT (Reactant), RACT (Reactant or reagent) (fluorination, stereoselective, of alkenes via epoxidn., fluoride ring opening, and reaction with diethylaminosulfur trifluoride, vicinal difluoroalkanes from); 7206-17-9P (trans-6-Dodecene); 7206-29-3P (cis-6-Dodecene) Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. and epoxidn. of, with monoperphthalic acid); 130876-18-5P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. and fluorination of); 92943-15-2P (cis-6,7-Epoxydodecane); 92943-16-3P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. and ring opening of, with hydrogen fluoride-triethylamine complex); 119105-44-1P; 119105-45-2P Role: SPN (Synthetic preparation), PREP (Preparation) (prepn. of); 4762-26-9 (Hexyl triphenylphosphonium bromide) Role: RCT (Reactant), RACT (Reactant or reagent) (stereoselective Wittig reaction of, with hexanal); 66-25-1 (Hexanal) Role: RCT (Reactant), RACT (Reactant or reagent) (stereoselective Wittig reaction of, with hexyltriphenylphosphonium bromide)
Date de création de la notice
2006-03-03
