Page 68 - Mechanism and Theory in Organic Chemistry

Chapter 2

SOME FUNDAMENTALS

OF PHYSICAL

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ORGANIC CHEMISTRY

In this chapter we review several aspects of the physical chemistry of organic com-
pounds that are particularly useful in the investigation of reaction mechanisms.

2.1 STEREOCHEMISTRY

Because of the excellent introduction to stereochemistry that is included in most
introductory organic textbooks, we shall limit our discussion to reviewing the
meaning of a number of terms. The reader who wishes more information is
referred to other s0urces.l
Two compounds are stereoisomers of one another if the bonding arrangement
in one is identical to that in the other except in the way the atoms are oriented in
space. Thus, 1 and 2, 3 and 4, 5 and 6, 7 and 8 are four pairs of stereoisomers.
There are two types of stereoisomers : enantiomers and diasteriomers.
Enantiomers are nonsuperimposable mirror images of one another. Thus, for
example, R-lactic acid (1) is the enantiomer of S-lactic acid (2). And allene 3 is
the enantiomer of allene 4. Molecules that are not superimposable on their mirror

' For the best discussions in introductory textbooks, see: (a) R. T. Morrison and R. N. Boyd,
Organic Chemistry, 3rd edn., Allyn & Bacon, Boston, 1973, pp. 73-80, 115-140, 225-246; (b) J. B.
Hendrickson, D. J. Cram, and G. S. Hammond, Organic Chemistry, 3rd edn., McGraw-Hill, New
York, 1970, pp. 175-230; (c) N. L. Allinger, M. P. Cava, D. C. DeJong, C. R. Johnson, N. A. Lebel,
and C. L. Stevens, Organic Chemistry, Worth, New York, 1971, pp. 105-126. More thorough intro-
ductions are available in the two small books; (d) G. Natta and M. Farina, Stereochemisty,
Harper & Row, New York, 1972; (e) K. Mislow, Introduction to Stereochemirtry, W. A. Benjamin,
Menlo Park, Calif., 1966. A number of larger, more advanced treatments are also available. See, for
example: (f) M. S. Newman, Steric Efects in Organic Chemirty, Wiley, New York, 1956; (g) E. L.
Eliel, Stereochemisty of Carbon Compounds, McGraw-Hill, New York, 1962.