The pyrethroid class consists of a complex mixture of stereoisomers with at least one chiral center
, which is a mixture of two molecules that can act distinctly at the enzymatic sites of a cell.
In nature, cathinone exists as a racemic mixture that contains one chiral center
which means that it has two enantiomers and commonly one of them will have greater psychological effect in human biological system than the other enantiomer .
These methods construct deoxypropionate units in a linear-iterative fashion, and one iteration cycle typically requires 3-6 steps to introduce one methyl-branched chiral center
The nerolidol molecule contains a chiral center
and a double bond-generating cis/trans isomerism, resulting in four possible stereoisomers in a mixture.
Therefore, the phosphorus atom can act as a chiral center
unlike a nitrogen atom.
Since chiral center
is present in the side chain of d-TRS.
Finally, some of the newest results indicate the possibility to induce chirality in nonchiral liquid crystalline azobenzene polymers, even in the absence of any structural chiral center
, simply by irradiating with appropriate circularly polarized light.
Dimebu (3,3-dimethylbutyl methylphosphonofluoridate) (5), an isomer of soman with only one chiral center
, P([+ or -]), is also hydrolyzed by IBA-[Beta]CD.
In addition, they can be used to predict the absolute configuration of the chiral center
in many instances.
Later a new synthetic strategy was developed which involved the introduction of the chiral center
in the very first step using an enantiomerically pure amino acid which led to the synthesis of enantiomerically pure quinazolinones nucleus.
Many chemical compounds used in the formulation of drugs have one or a few chiral centers
. Various enantiomers of the chiral compounds show different biological activities in the living systems during the medical and pharmaceutical processes.