Total Synthesis of Artapilosine A and Artapilosine B

Artapilosines A and B, isolated from <i>Artabotrys pilosus</i>, demonstrated significant anti-HIV reverse transcriptase activity. In this work, we present the first asymmetric total synthesis of (-)-artapilosine A and of its enantiomer (+)-artapilosine A, achieved in 10 steps with overall yields of 0.9% and 0.7%, respectively, starting from commercially available piperonylic acid. The key step in this synthesis involved a pivotal photocyclization reaction, providing an efficient protocol for constructing the phenanthrene ring system common to many natural products. Additionally, using the same photocyclization strategy, we successfully synthesized artapilosine B in 10 steps with an overall yield of 2.1%.