Multibridged [3 n ]Cyclophanes, 1. Synthesis of [3 4 ](1,2,3,5)‐ and ‐(1,2,4,5)Cyclophanes

The acid-catalyzed cyclization of a pseudogeminally substituted acetyl group and a chloromethyl group of tri-bridged cyclophane 7, followed by reduction of the carbonyl group afforded [3 4 ](1,2,3,5)cyclophane 3. One-step TosMIC coupling reaction of tetrabromide 12 and subsequent reduction of the carbonyl groups provided an isomer of 3, [3 4 ](1,2,4,5)cyclophane 4