Synthesis of substituted 2‐amino‐3‐cyanodihydrofurans from styrene oxides and malononitrile

The reaction of styrene oxides with the malononitrile anion leads to the formation of 2‐amino‐3‐eyano‐5‐aryl‐4,5‐dihydrofurans (III), while a similar reaction with β,β‐dimethylstyrene oxides leads to 2‐amino‐3‐cyano‐4‐aryl‐5,5‐dimethyI‐4,5‐dihydrofurans (V). Therefore steric factors may play a significant role in the site of attack of the malononitrile anion on the oxide. Compounds of type V are more conveniently obtained from the cyanolaetones (VI) by rearrangement and dehydration.