As a further step, we now report the synthesis of 3,4-vinylenedioxythiophene (VDOT) 1 in which the ethylene bridge of EDOT has been replaced by a vinylene one. 9 The dimer 2 has also been synthesized as a model compound and its structure analyzed by X-ray diffraction. ... Scheme 1 Reagents and conditions: i) 2-iodoethanol, PTSA, toluene, reflux; ii) t-BuOK, t-BuOH, reflux; iii) 2.5% mol. 2nd generation Grubbs catalyst, toluene, reflux; iv) n-BuLi, THF, −70 ...