Friedländer-Type Reaction of 4-Cholesten-3-one with 2′-Aminoacetophenone: Angular versus Linear Quinoline-Fused Steroids

To optimize the experimental conditions used for the Friedländer-type condensation, an angular fused 4-substituted quinoline steroid has been obtained in very high yield and regioselectivity using readily available 4-cholesten-3-one and 2′-aminoacetophenone. Moreover, by varying the reaction conditions and the catalyst, the corresponding linear regioisomer was also achieved with an acceptable isolated yield and high chemoselectivity. Both structures have been definitively elucidated via 2D-NMR and fully characterized.