851387-46-7Relevant academic research and scientific papers
Enantioselective, (-)-sparteine-mediated deprotonation of geranyl and neryl N,N-diisopropylcarbamate: Configurational stability of the intermediate lithium compounds
Zeng, Wenbin,Fr?hlich, Roland,Hoppe, Dieter
, p. 3281 - 3287 (2005)
(E)/(Z)-Isomeric allylic carbamate esters were deprotonated by n-butyllithium/(-)-sparteine in toluene. Trapping experiments with chlorotrimethylsilane afforded the α-substitution products, with (R)-configuration, revealing that the pro-S proton is removed predominantly to form the corresponding (S)-lithium·(-)-sparteine derivatives; k S/kR>15:1 and >7:1, respectively. A slow (S)→(R)-epimerization occurs at -78°C (T1/2>60 min). The allylic double bond is stable to (Z)-(E) isomerization under these conditions.
