Synthesis of 2-(1-alkenyl)furans and 2-(1,3-alkadienyl)furans

Treatment of the compounds HOCH2CHC(CH3)CCCH(R)OCH3 (R = H or CH3) and HOCH2CHC(CH3)CCC(R1)C(R2)CH2OCH3 (R1 and R2 = H or CH3) with potassium tert-butoxide in dimethyl sulfoxide affords 2-(1-alkenyl)furans and 2-(1,3-alkadienyl)furans, respectively, in good yields.