134303-01-8Relevant academic research and scientific papers
Synthesis of optically active C-allylglycine derivatives and conversion into isoquinolones
Zhang, Nong,Nubbemeyer, Udo
, p. 242 - 252 (2007/10/03)
C-Allylglycyl amides can be efficiently synthesized via an auxiliary controlled diastereoselective aza-Claisen rearrangement. The stereodirecting unit is placed on an auxiliary derived from commercially available (S)-proline. After N-allylation, the obtained optically active allylamines were reacted with various N-protected glycyl fluorides to give the (2R)-C-allylglycyl amides in good yields. The diastereoselectivity of the asymmetric allylation varied between 1:1 and > 1:15 depending on the N-protective group, the auxiliary, and the reaction temperature. Likewise, the C-allylglycine derivatives can be used as monomers in peptide synthesis to synthesize (R)-proline derivatives or chiral isoquinolones; the latter should serve as building blocks in the total syntheses of alkaloids.
Synthesis of 15-azayohimban, a new heterocyclic ring system
Valls,Segarra,Maillo,Bosch
, p. 1065 - 1074 (2007/10/02)
Two synthetic routes to the 15-azayohimban ring system have been studied. The first one, based on a Pictet-Spengler condensation between tryptamine and piperidine acetal 4, gave very low yields of pentacycles 2a. The second, more efficient route involves as the crucial step a cyclization of a N-acyliminium cation generated from imide 11. The different course of the Pictet-Spengler reaction from amino acetals 4 and 8, as compared with amido acetal 7, is discussed.
