Synthesis of reverse fleximer truncated carbocycles. Conditions: (a) for 3a and 4a, 12 or 9 respectively, tributylstannyl thiophene, dioxane, PdCl2(PPh3)2, reflux; for 3b and 4b, 12 or 9, respectively, tributylstannyl furan, dioxane, PdCl2(PPh3)2, reflux for 3c and 4c, 12 or 9, respectively, tributylstannyl thiazole, dioxane, Pd(PPh3)4, reflux; (b) TFA:H2O (2:1) in THF, r.t., 6 hours. Yield over two steps: for 3a yield: 90%; for 3b yield: 90%; for 3c yield: 89%; for 4a yield: 55%; for 4b yield: 58%; for 4c yield: 42%.