10.1021/jo060592p.s001 Marisa Mena Marisa Mena Josep Bonjoch Josep Bonjoch Domingo Gomez Pardo Domingo Gomez Pardo Janine Cossy Janine Cossy Ring Expansion of Functionalized Octahydroindoles to Enantiopure <i>cis</i>-Decahydroquinolines<sup>†</sup> American Chemical Society 2006 ci ring Expansion reaction conditions MsCl THF analogue AgOAc ethylene isomer acetal Endo ring enlargement rt Et 3N TFAA Enantiopure exo derivatives benzyl Functionalized Octahydroindoles endo enantiopure hydroxyethyl entry 2006-08-04 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Ring_Expansion_of_Functionalized_Octahydroindoles_to_Enantiopure_i_cis_i_Decahydroquinolines_sup_sup_/3066568 A new synthetic entry to enantiopure <i>cis</i>-decahydroquinolines is reported. Endo and exo derivatives of <i>cis</i>-1-benzyl-2-(hydroxymethyl)octahydroindol-6-one ethylene acetal undergo ring enlargement upon treatment with TFAA and then Et<sub>3</sub>N (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 (2<i>S</i>,1‘<i>R</i>) endo isomer, which under kinetic reaction conditions (MsCl, THF, −20 °C, then AgOAc at rt ) gives the expanded product in 54% yield.