0000000000146871
AUTHOR
Alexander B. Terentiev
Difference in the behavior of methyl (S)-?-bromopropionate in its addition to trimethylvinylsilane depending on the method of initiation
The addition of methyl (S)-2-bromopropionate to trimethylvinylsilane initiated by systems based on iron pentacarbonyl affords a racemic adduct and is accompanied by racemization of the unreacted chiral ester. In the presence of benzoyl peroxide, the reaction proceeds similarly, but no racemization of the starting chiral ester occurs.
The identification of vicinally substituted cyclohexane isomers in their mixtures by 1H and 13C NMR spectroscopy.
The radical addition reactions of organobromine compounds, XBr (X = CH2COOMe, PhCH2, CHBr2 and CCl3) with cyclohexene afforded mixtures of cis/trans isomer pairs of 1-X-2-Br-cyclohexanes. In addition to benzyl benzoyloxy derivatives are formed also, when benzoyl peroxide is used as an initiator. Owing to the great difficulties in separating these cis/trans isomer pairs, they are identified directly in their mixtures by NMR spectroscopy. In addition to one-dimensional (ID) 1H, proton decoupled 13C and DEPT-135, also two-dimensional (2D) 13C-13C INADEQUATE as well as 1H-13C HMQC experiments have been used in assigning the signals of each compound in their mixtures. The identification of each …