Synthesis and reactions of 2,2-dicyano oxiranes and 2-cyano 2-alkoxycarbonyl oxiranes are reviewed within the scope of application to the synthesis of some interesting compounds. The nucleophilic attacks on the nitrile group or the ester group give new functionalized epoxides. The regioselective ring opening is followed by hydrogen cyanide elimination to give cyanoformyl derivatives or α-keto esters which are electrophilic compounds. On the other hand, oxiranes readily furnish, on heating, carbonyl ylids which are trapped by dipolarophiles. The high regio and chemo selectivity of the reactions prove the interest of these epoxides.