2,6-Dimethylpiperidines are

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

s with the formula C₅H₈(CH₃)₂NH. Three

stereoisomer In stereochemistry, stereoisomerism, or spatial isomerism, is a form of isomerism in which molecules have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in ...

s exist: the achiral (''R'',''S'')-isomer and the

chiral Chirality () is a property of asymmetry important in several branches of science. The word ''chirality'' is derived from the Greek language, Greek (''kheir''), "hand", a familiar chiral object. An object or a system is ''chiral'' if it is dist ...

(''R'',''R'')/(''S'',''S'')

enantiomer In chemistry, an enantiomer (Help:IPA/English, /ɪˈnænti.əmər, ɛ-, -oʊ-/ Help:Pronunciation respelling key, ''ih-NAN-tee-ə-mər''), also known as an optical isomer, antipode, or optical antipode, is one of a pair of molecular entities whi ...

ic pair. Dimethylpiperidines are derivatives of the

heterocycle A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic organic chemistry is the branch of organic chemistry dealing with the synthesis, proper ...

piperidine Piperidine is an organic compound with the molecular formula (CH2)5NH. This heterocyclic amine consists of a six-membered ring containing five methylene bridges (–CH2–) and one amine bridge (–NH–). It is a colorless liquid with an odor de ...

, wherein two hydrogen atoms are replaced by

methyl In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula (whereas normal methane has the formula ). In formulas, the group is often abbreviated as ...

groups. The 2,6-dimethylpiperidines are prepared by reduction of

2,6-dimethylpyridine 2,6-Lutidine is a natural heterocyclic compound, heterocyclic aromaticity, aromatic organic compound with the formula (CH3)2C5H3N. It is one of several methyl group, dimethyl-substituted derivative of pyridine, all of which are referred to as Luti ...

(2,6-lutidine). The achiral isomer is the predominant isomer produced in this reaction. The 2,6-dimethylpiperidines are of interest for their conformational properties. The (''R'',''S'')-isomer exists largely in the

chair conformation Cyclohexane conformations are any of several three-dimensional shapes adopted by cyclohexane. Because many compounds feature structurally similar six-membered rings, the structure and dynamics of cyclohexane are important prototypes of a wide r ...

with equatorial methyl groups. The (''R'',''R'')/(''S'',''S'')-isomers are attractive chiral

secondary amine In chemistry, amines (, ) are organic compounds that contain carbon-nitrogen bonds. Amines are formed when one or more hydrogen atoms in ammonia are replaced by alkyl or aryl groups. The nitrogen atom in an amine possesses a lone pair of elec ...

building blocks.Einhorn, J.; Einhorn, C.; Ratajczak, F.; Durif, A.; Averbuch, M.-T. and Pierre, J.-L., "Synthesis and resolution of a chiral analog of 2,2,6,6-tetramethylpiperidine and of its corresponding

nitroxide Aminoxyl denotes a radical functional group with general structure R2N–O•. It is commonly known as a nitroxyl radical or a nitroxide, however IUPAC discourages the use of these terms, as they erroneously suggest the presence of a nitro group. ...

", Tetrahedron Letters, 1998, volume 39, pages 2565-2568

References

See also