218460-59-4Relevant academic research and scientific papers
A new synthesis of α-amino acid thioesters by pummerer reaction of 3- substituted-4-sulfinyl-β-sultams
Iwama, Tetsuo,Kataoka, Tadashi,Muraoka, Osamu,Tanabe, Genzoh
, p. 8355 - 8360 (2007/10/03)
α-Amino acid thioesters were synthesized by the Pummerer reaction of 3- substituted-4-sulfinyl-β-sultams with TFAA. The 3-substituted-4-sulfinyl- β-sultams were prepared from the corresponding β-sultams by sulfenylation with diphenyl disulfide followed by m-CPBA oxidation. Diastereoselective synthesis of β-sultams by 1,3-asymmetric induction in [2 + 2] cycloaddition of a sulfene intermediate and chiral imines in solution-phase was studied, and it was found that N-alkylimines gave better diastereoselectivities than N-aralkylimines. The use of imines derived from (R)- and (S)-α- methylbenzylamine followed by separation of the major and minor diastereomers gave enantiopure 3-substituted-N-methylbenzyl-β-sultams. These β-sultams were then converted to N-methylbenzyl-α-amino acid thioesters via sulfenylation and Pummerer rearrangement with high or complete retention of configuration.
