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Configurational Stability of Unsubstituted Cyclohexyllithium
Author(s) -
Lambert Joseph B.,
Majchrzak Michal W.,
Rosen Bruce I.,
Steele Kent P.,
Oliver Sarah Ann,
UrdanetaPérez Migdalia
Publication year - 1980
Publication title -
israel journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.908
H-Index - 54
eISSN - 1869-5868
pISSN - 0021-2148
DOI - 10.1002/ijch.198000069
Subject(s) - chemistry , racemization , reagent , steric effects , pentane , magnesium bromide , yield (engineering) , stereoselectivity , deuterium , bromide , proton , medicinal chemistry , lithium (medication) , cyclohexanol , stereochemistry , computational chemistry , magnesium , organic chemistry , catalysis , thermodynamics , medicine , physics , quantum mechanics , endocrinology
The configurational stability of cyclohexyllithium was examined by the proton label method without the influence of perturbing substituents. According to this method, configurational changes are followed by the steric arrangement of protons and deuterons. The desired labeling pattern was obtained by conversion of cyclohexanol‐ 2,2,6‐d 3 (1H and 6H either cis or trans) to bromocyclohexane‐ 2,2,6‐d 3 . Good yield and high stereoselectivity was achieved by formation of the tosylate and treatment of the tosylate with magnesium bromide. The two stereoisomers of bromocyclohexane‐ 2,2,6‐d 3 were allowed to react separately with lithium in pentane. The separate reactions give the same racemized mixture of cyclohexanecarboxylic‐ 2,2,6‐d 3 acids after treatment with CO 2 . The racemization probably occurs during formation of the organolithium reagent on the surface of the metal or during the lifetime of a short‐lived radical intermediate. It is not likely that the aggregated organolithium reagent itself undergoes racemization.