Formal synthesis of (-)-vallesamidine a 2,2,3-trialkylindoline alkaloid

Article abstract of DOI:10.1016/S0957-4166(00)80350-X

(S)-(+)-2-ethyl-2[2'-carboxymethyl]cyclopentanone 6 was prepared regio- and enantioselectively (ee = 90%) by 'deracemizing alkylation' of the chiral imine 5 with methylacrylate. Compound 6 was transformed into the bicyclic imine (R)-(+)-3. This intermediate was used by Heatcock, in the racemic form, to the total synthesis of (±)-Vallesamidine 1, a 2,2,3-trialkylindoline alkaloid.