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The regioselective synthesis of pyrano[3,2- e ]indole alkaloid fontanesine B by two different cyclizations is described. The complete regioselectivity is controlled by the C4 Pictet-Spengler cyclization, in which an iminium ion acts as a transient directing (TDG) group. Furthermore, carbolines were constructed by a new Bischler-Napieralski-type cyclization, in which an unprecedented trichloromethyl carbamate serves as a reactive group., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)