Cryptochirality in stereochemistry is a special case of chirality where due to the electronic properties of the chiral molecule its specific rotation is non-measurable. The term was introduced by K. Mislow in 1977. The different types of isomers. ... The term chiral (pronounced ki-rall) is used to describe an object which is non-superimposable on its mirror image. ... The specific rotation of a chemical compound [α]D is defined as the observed optical rotation (a) when light of 589 nanometer wavelength is passed through a sample with a sample path (l) of 0. ...

For example the alkane 5-ethyl-5-propylundecane or (n-butyl)ethyl(n-hexyl)(n-propyl)methane found in certain species of Phaseolus vulgaris has two enantiomeric forms without any observable optical rotation ^[1] An alkane in organic chemistry is a saturated hydrocarbon without cycles, that is, an acyclic hydrocarbon in which the molecule has the maximum possible number of hydrogen atoms and so has no double bonds. ...

It is still possible to distinguish between the two enantiomers by asymmetric synthesis with the (S)-alkane 3 in a autocatalytic system of the achiral aldehyde 1 ^[2] and achiral Diisopropylzinc 2 to the chiral (R)-alcohol 4 with enantiomeric excess 94%: The two optical isomers of bromochlorofluoromethane Chiral synthesis (also called asymmetric synthesis) is organic synthesis which preserves or introduces a desired chirality. ... A single chemical reaction is said to have undergone autocatalysis, or be autocatalytic, if the reaction product is itself the catalyst for that reaction. ... An aldehyde is either a functional group consisting of a terminal carbonyl group or a compound containing a terminal carbonyl group. ... In chemistry, an alcohol is any organic compound in which a hydroxyl group (-OH) is bound to a carbon atom of an alkyl or substituted alkyl group. ... In chemistry two stereoisomers are said to be enantiomers if one can be superimposed on the mirror image of the other. ...

For chiral induction to be possible C-H bonds in the alkane are believed to interact with the pi electrons of the aldehyde. Geometry of the water molecule Molecules have fixed equilibrium geometries--bond lengths and angles--that are dictated by the laws of quantum mechanics. ...

Cryptochirality also occurs in polymeric systems growing from chiral initiators for example in dendrimers with lobes of different size attached to a central core ^[3]. Polymer is a generic term used to describe a very long molecule consisting of structural units and repeating units connected by covalent chemical bonds. ... Another meaning of initiator is SCSI initiator. ... A dendrimer is a molecule with a form like the branches of a tree. ...

See also

• More on diisopropylzinc autocatalysis see: homochirality

In chemistry, a molecule is chiral if it is not superimposable on its mirror image regardless of how it is contorted. ...

References

1. ^ Chiral Discrimination of Cryptochiral Saturated Quaternary and Tertiary Hydrocarbons by Asymmetric Autocatalysis Kawasaki, T.; Tanaka, H.; Tsutsumi, T.; Kasahara, T.; Sato, I.; Soai, K. J. Am. Chem. Soc.; (Communication); 2006; 128(18); 6032-6033. Abstract
2. ^ 2-(3,3-dimethylbut-1-ynyl)pyrimidine-5-carbaldehyde
3. ^ Cryptochirality and dendrimers Struijk, MP Peerlings, HWI Meijer, EW Polymer Preprints 37(2), 497-498 (1996) Article