As shown in Scheme [³] , we started our attempts by modification of the preparation of cyclization precursors. We found that etherification by directly using 2-aminophenol could proceed smoothly in a mixed solvent at 0 ˚C to afford 3a in 81% yield. [8] This success allows further shortening of the previous five-step procedure to two steps because reduction of nitro group was omitted. Next, we explored the possible reaction conditions for CuI/l-proline-catalyzed ...