PrCHBrCH2CHPrR (R = Br, F, or I) were converted into 1,2-dipropylcyclopropane by various metallic or organometallic reducing agents. Normally, cyclization occurred in a stereoconvergent manner, i.e. diastereomeric dihalides usually led to the same mixt. of cis-trans isomeric reaction products, indicating a nonconcerted cleavage of the 2 halogen atoms. The isomer ratios depended very strongly on the nature of the reducing agents and on possible salt additives, probably typical for reactions of short-lived intermediates and compatible with the assumed one-electron transfer mechanism. The \"endo tendency\" was obsd. again: the cis-disubstituted cyclopropane though thermodynamically less stable than the trans isomer was formed predominantly in most cases. [on SciFinder (R)]
Title
Verlaufen 1,3-Eliminierungen konzertiert oder nicht ?
Published in
Chemische Berichte
Volume
107
Issue
4
Pages
1171-1187
Date
1974
Note
CAN 81:12985 22-9 Physical Organic Chemistry Inst. Chim. Org.,Univ. Lausanne,Lausanne,Switz. Journal 0009-2940 written in German. 36685-03-7 Role: RCT (Reactant), RACT (Reactant or reagent) (bromination of); 357-83-5 Role: RCT (Reactant), RACT (Reactant or reagent) (fluorination of nonanols by); 5932-79-6 Role: RCT (Reactant), RACT (Reactant or reagent) (halogenation of); 36685-01-5P; 36685-02-6P; 52708-05-1P; 52708-06-2P; 52708-07-3P; 52708-08-4P; 52708-09-5P; 52708-10-8P; 52708-11-9P; 52708-12-0P; 52708-13-1P; 52708-14-2P; 52708-15-3P; 52708-16-4P; 52745-78-5P; 52745-79-6P Role: SPN (Synthetic preparation), PREP (Preparation) (prepn. of); 7642-15-1; 14850-23-8 Role: RCT (Reactant), RACT (Reactant or reagent) (reaction of, with diiodomethane); 75-11-6 Role: RCT (Reactant), RACT (Reactant or reagent) (reaction of, with octene); 594-19-4; 598-30-1; 892-20-6; 1068-55-9; 13931-95-8; 37352-24-2 Role: PRP (Properties) (reductive cyclization of 4,6-dihalononanes by); 7440-66-6 Role: RCT (Reactant), RACT (Reactant or reagent) (reductive cyclization of 4,6-dihalononanes by); 7439-93-2 Role: RCT (Reactant), RACT (Reactant or reagent) (reductive cyclization of 4,6-dihalononanes by biphenyl and); 632-51-9 Role: PRP (Properties) (reductive cyclization of 4,6-dihalononanes by lithium and); 91-20-3; 92-52-4 Role: RCT (Reactant), RACT (Reactant or reagent) (reductive cyclization of 4,6-dihalononanes by lithium and); 7440-23-5 Role: RCT (Reactant), RACT (Reactant or reagent) (reductive cyclization of 4,6-dihalononanes by potassium and); 7440-09-7 Role: RCT (Reactant), RACT (Reactant or reagent) (reductive cyclization of 4,6-dihalononanes by sodium and); 109-72-8 Role: RCT (Reactant), RACT (Reactant or reagent) (with dibromononane)
Record creation date
2006-03-03
