Short, Scalable Access to Pyrrovobasine.

A concise gram-scale synthesis of pyrrovobasine ( 1 ) is reported. Key transformations include a three-step decagram-scale synthesis of the tetracyclic compound, Mn-mediated direct radical cyclization, and the introduction of a naturally rare pyrraline structure. The synthesis is designed to be applicable to gram-scale synthesis using inexpensive and readily available reagents.