Síntese de pró-α-aminoácidos e pró-α-aminoamidas: ensaios de reduções diastereoespecíficas

Abstract

Chirality is a property of some molecules related to their spatial (three-dimensional) structures. This property is linked to symmetry since, to be chiral, the molecule cannot admit any improper axis of rotation, that is, it cannot perform the S operation. Chirality, as a molecular property, is recognized by optical activity, since a chiral molecule deviates the plane of polarized light. The number of possible isomers of a given substance is given by the formula 2n, where n is the number of chiral and/or stereogenic centers. When two optical isomers are mirror images of each other they are called enantiomers, when they are not, they are called diastereomers. In nature, among organic molecules, only one of the optical isomers is generally found, as living organisms produce them in this way. This is due to the fact that biological receptors, as well as enzymes, also possess chirality, recognizing or biosynthesizing only one of the enantiomers1. Several biological or pharmacological activities can be related to the structure, or to the structural differences between isomers. An example is limonene which, when with the S (1) configuration, has a lemon-like aroma, while the R (2) configuration has an orange aroma.