Novel [6]phenacenes (fulminenes) with two long alkyl chains at the axis positions were synthesized. This short synthesis comprises the following three steps: (1) ruthenium-catalyzed direct C-H bond arylation; (2) conversion of directing groups by Wittig reaction; and (3) bismuth- or gold-catalyzed cyclization of vinyl ether. Organic field-effect transistor devices fabricated with a thin film of 3,11-di(tetradecyl)fulminene exhibited typical p-channel normally-off properties.