First total synthesis of the 1,2,3,4-tetrahydronaphtho[2,1-f]isoquinoline annoretine

Here we describe the first total synthesis of the 1,2,3,4-tetrahydronaphtho[2,1-f]isoquinoline (6) annoretine from N-carbethoxy-o-styrylphenylethylamines 2. The key steps were the Bischler–Napieralski reaction to form the isoquinoline unit and photocyclization of the resulting 5-styrylisoquinoline 3 to naphtoisoquinoline 4.