John C. Sheehan

John Clark Sheehan
Born	(1915-09-23)September 23, 1915 Battle Creek, Michigan, U.S.
Died	March 21, 1992(1992-03-21) (aged 76) Key Biscayne, Florida, U.S.
Alma mater	Battle Creek College University of Michigan
Known for	Synthesis of penicillin
Awards	ACS Award in Pure Chemistry (1951) Election to National Academy of Sciences (1957) American Chemical Society Award for Creative Work in Synthetic Organic Chemistry (1959) John Scott Award for inventors benefiting mankind (1964) Outstanding Achievement Award of the University of Michigan (1971) Oesper Award (1982)[1]
Scientific career
Fields	Organic chemistry
Institutions	Massachusetts Institute of Technology, Merck & Co.
Doctoral advisor	Werner E. Bachmann
Notable students	E.J. Corey

John Clark Sheehan (September 23, 1915 – March 21, 1992) was an American organic chemist whose work on synthetic penicillin led to tailor-made forms of the drug. After nine years of hard work at the Massachusetts Institute of Technology (M.I.T.), he became the first to discover a practical method for synthesizing penicillin V. While achieving total synthesis, Sheehan also produced an intermediate compound, 6-aminopenicillanic acid, which turned out to be the foundation of hundreds of kinds of synthetic penicillin. Dr. Sheehan's research on synthetic penicillin paved the way for the development of customized forms of the lifesaving antibiotic that target specific bacteria. Over the four decades he worked at M.I.T., Sheehan came to hold over 30 patents, including the invention of ampicillin, a commonly used semi-synthetic penicillin that is taken orally rather than by injection. His research covered not only penicillin, but also peptides, other antibiotics, alkaloids, and steroids.