BY LEO A. PAQUETTE AND MILTON ORCHIN

EVERY UNDERGRADUATE STUDENT enrolled in a course dealing with organic chemistry is quickly made familiar with the Newman Projection, named after Melvin Newman, because this method of representing the geometry of organic molecules appears in practically every text of organic chemistry. As originally suggested by Newman in 1952, this technique involves looking down the bond between two connected (sp³-hybridized) carbon atoms and projecting the three-dimensional structure around this bond onto a plane surface. For example, the simple two-carbon compound ethane is represented in a line formula by CH₃-CH₃ and conventionally by the side-on perspective (sawhorse) formula (see A below). The arms of the Y and the inverted Y are understood to represent the six hydrogen atoms, the points at the intersection of the arms represent the carbon atoms, and the diagonal line connecting the Y's represents the carbon-carbon bond. In the Newman projection (see B below) the view of the molecule is not