A group of Harvard scientists working with a research group in Sweden successfully synthesized the chemical which causes asthma attacks and other severe allergic reactions.

Dr. Elias J. Corey, Sheldon Emery Professor of Organic Chemistry and head of the Harvard research group, said yesterday the discovery could speed the development of a treatment for asthma and other allergic reactions.

The substance, known as slow reacting substance (SRS) of anaphylaxis, is a potent muscle-contractant. When foreign substances, such as insect venom, enter the body, antibodies trigger the release of SRS.

The previous lack of SRS in large quantities kept scientists from developing an "anti-SRS" substance to counter its effects. "Medical studies can now proceed with pure SRS" in sufficiently large quantities, Corey said.

SRS is stronger and more effective than the other substance known to cause asthma attacks, histamine. While scientists developed anti-histamine years ago, the substance "is not very effective in treating asthma." Corey said. Scientists expect an "anti-SRS" substance will combat asthma more effectively.

The Harvard group worked in conjunction with scientists at the Karolinska Institute in Sweden. The project began in 1977 over lunch at a Harvard Square restaurant, Corey said.

The findings were published in the Journal of the American Chemical Society.