jo060592p_si_001.pdf (3.98 MB)
Ring Expansion of Functionalized Octahydroindoles to Enantiopure cis-Decahydroquinolines†
journal contribution
posted on 2006-08-04, 00:00 authored by Marisa Mena, Josep Bonjoch, Domingo Gomez Pardo, Janine CossyA new synthetic entry to enantiopure cis-decahydroquinolines is reported. Endo and exo derivatives of
cis-1-benzyl-2-(hydroxymethyl)octahydroindol-6-one ethylene acetal undergo ring enlargement upon
treatment with TFAA and then Et3N (thermodynamic conditions) to give enantiopure 1-benzyl-3-hydroxydecahydroquinolin-7-one derivatives in 77 and 82% yield, respectively. For 2-(1-hydroxyethyl)
analogues, the best synthetic result is obtained from the (2S,1‘R) endo isomer, which under kinetic reaction
conditions (MsCl, THF, −20 °C, then AgOAc at rt ) gives the expanded product in 54% yield.