a novel synthesis of methacrylic acid and methacrolein from isobutylene oxide is provided . this method includes contacting isobutylene oxide with a catalyst , preferably a heteropolyacid catalyst , in the presence of oxygen . using this method , isobutylene oxide conversion is nearly 100 % complete . depending upon the reaction temperature selected , yields of up to about 60 % methacrolein and up to about 12 % methacrylic acid may be obtained . a simple , inexpensive high yield process is thus provided for producing reaction mixtures containing methacrylic acid and methacrolein .