226899-29-2Relevant academic research and scientific papers
Asymmetric induction through metalation of chiral dithioacetals and oxathioacetals
Zaidi, Javid H.,Gunjial, Naseem Iqbal
, p. 2835 - 2845 (2008/03/11)
The work presented in this article consists of synthesis of chiral dithioacetals and oxathioacetals using pure chiral auxiliaries, such as, (+) camphor, (-) menthol, and L-cysteine. Metalation of these chiral dithioacetals and oxathioacetals, followed by nucleophilic addition to benzaldehyde and removal of chiral auxiliary, furnished scalemic mandelic acid with various enantiomeric purities. Copyright Taylor & Francis Group, LLC.
A new efficient method for S-CH2-S bond formation and its application to a djenkolic acid-containing cyclic enkephalin analog
Ueki, Masaaki,Ikeo, Takayoshi,Hokari, Kumiko,Nakamura, Keiko,Saeki, Akihiko,Komatsu, Hiroshi
, p. 829 - 838 (2007/10/03)
An efficient methylene insertion reaction to construct an S-CH2-S bridge between two cysteine residues occurred when the thiol-protecting dimethylphosphinothioyl (Mpt) group of Z-Cys(Mpt)-OMe was removed with tetrabutylammonium fluoride hydrate in CH2Cl2. The thiol-free form gave similar results, albeit the yields were somewhat lower. In both cases, the best yields were obtained using 2 molar amounts of the reagent. Higher amounts of the reagent reduced the yield because of dehydroalanine formation. In the case of penicillamine, the thiol-free form was better in reactivity than the S-Mpt form, which required double the amount of the reagent to give the same yield. The reaction was successfully used in a synthesis of a cyclic enkephalin analog with the S-CH2-S bridge.
