The NMR database method enables identification of the stereochemistry of chiral

Chirality (chemistry)

A chiral molecule is a type of molecule that lacks an internal plane of symmetry and thus has a non-superimposable mirror image. The feature that is most often the cause of chirality in molecules is the presence of an asymmetric carbon atom....

 molecules, especially polyol

Polyol

A polyol is an alcohol containing multiple hydroxyl groups. In two technological disciplines the term "polyol" has a special meaning: food science and polymer chemistry.- Polyols in food science :...

s. It relies on the observation that NMR spectroscopy

NMR spectroscopy

Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy, is a research technique that exploits the magnetic properties of certain atomic nuclei to determine physical and chemical properties of atoms or the molecules in which they are contained...

 data depend only on the immediate environment near an asymmetric carbon

Asymmetric carbon

An asymmetric carbon atom is a carbon atom that is attached to four different types of atom or four different groups of atoms. Knowing the number of asymmetric carbon atoms, one can calculate the maximum possible number of stereoisomers for any given molecule as follows:As an example, malic acid...

, not on the entire molecular structure. All stereoisomers of a certain class of compounds are synthesized, and their proton NMR

Proton NMR

Proton NMR is the application of nuclear magnetic resonance in NMR spectroscopy with respect to hydrogen-1 nuclei within the molecules of a substance, in order to determine the structure of its molecules. In samples where natural hydrogen is used, practically all of the hydrogen consists of the...

 and carbon-13 NMR

Carbon-13 NMR

Carbon-13 NMR is the application of nuclear magnetic resonance spectroscopy to carbon. It is analogous to proton NMR and allows the identification of carbon atoms in an organic molecule just as proton NMR identifies hydrogen atoms...

 chemical shift

Chemical shift

In nuclear magnetic resonance spectroscopy, the chemical shift is the resonant frequency of a nucleus relative to a standard. Often the position and number of chemical shifts are diagnostic of the structure of a molecule...

s and coupling constant

Coupling constant

In physics, a coupling constant, usually denoted g, is a number that determines the strength of an interaction. Usually the Lagrangian or the Hamiltonian of a system can be separated into a kinetic part and an interaction part...

s are compared. Yoshito Kishi

Yoshito Kishi

Yoshito Kishi is the Morris Loeb Professor of Chemistry at Harvard University. He is known for his contributions to the sciences of organic synthesis and total synthesis....

's group at Harvard University

Harvard University

Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...

has reported NMR databases for 1,3,5-triols 1,2,3-triols, 1,2,3,4-tetraols, and 1,2,3,4,5-pentaols.

The stereochemistry of any 1,2,3-triol may be determined by comparing it with the database, even if the remainder of the unknown molecule is different from the database template compounds.