Chiralitätserhaltung bei der enthalogenierenden Cyclopropan-Bildung aus optisch aktivem 4,6-Dibromnonan
Treatment of optically active (PrCHBr)2CH2 with Li-Hg or biphenyl-Li gave 46:54 or 59:51, resp., cis- and trans-1,2-dipropylcyclopropane (I). The original (R,R)-configuration at both chiral centers was inverted in the course of the cyclization reaction leading to the trans isomer. These stereochem. results ruled out clearly the possibility of the often discussed "p-cyclopropane" intermediate. [on SciFinder (R)]
1974
107
4
1162
70
CAN 81:12984 22-9 Physical Organic Chemistry Inst. Chim. Org.,Univ. Lausanne,Lausanne,Switz. Journal 0009-2940 written in German. 15489-27-7 Role: PRP (Properties) (Grignard reaction of bis(hydroxymethyl)cyclopropane derivs. in presence of); 74-96-4 Role: PRP (Properties) (Grignard reaction with bis(hydroxymethyl)cyclopropane derivs.); 37352-24-2 Role: PROC (Process) (cyclization of dibromononane in presence of); 7439-93-2 Role: USES (Uses) (cyclization of dibromononane in presence of biphenyl and); 92-52-4 Role: USES (Uses) (cyclization of dibromononane in presence of lithium and); 36685-07-1 Role: RCT (Reactant), RACT (Reactant or reagent) (cyclization of, stereochem. of); 36685-01-5P; 36685-02-6P; 36685-03-7P; 36685-04-8P; 36685-05-9P; 36685-06-0P; 52708-03-9P; 52708-04-0P; 52745-75-2P; 52745-76-3P; 52745-77-4P; 52749-15-2P Role: SPN (Synthetic preparation), PREP (Preparation) (prepn. of); 14090-88-1; 51152-15-9 Role: RCT (Reactant), RACT (Reactant or reagent) (redn. of)
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