After nine years of dogged work, Chemist John C. Sheehan of M.I.T. announced last week that he had discovered a practical method of synthesizing penicillin V, one of the two most useful forms of the natural antibiotic made by the penicillin mold.
Dr. Sheehan had solved one of modern chemistry's most baffling problems. During World War II a thousand chemists working in 39 laboratories in the U.S. and Britain spent an estimated $20 million trying to accomplish it. One researcher succeeded, but he could not figure out how he had done it and could never do it again. Another group produced a...