It07:Menthol

Menthol

Menthol

General
Systematic name	systematic name
Other names	(1S)-menthol (1S)-(1rH,4tH)-p-menthan-3t-ol (+)(1S)-Menthol (+)-menthol (1S,2R,5S)-(+)-menthol
Molecular formula	C₁₀H₂₀O
SMILES	O[C@@H]1C[C@H](C)CC[C@H]1[C@@H](C)C
Molar mass	156.27gmol^-1
Composition	c%H%O%
CAS number	89-78-1, 490-99-3, 491-01-0, 491-02-1, 1490-04-6(racemic mixture), 2216-51-5, 2216-52-6, 3623-51-6, 3623-52-7, 3623-53-8, 15356-60-2, 15356-70-4, 20747-49-3, 20752-33-4, 20752-34-5, 23283-97-8, 64282-88-8
Properties
Density & phase	0.891 g/cm³, solid
Melting point	41-42⁰C
Boiling point	103-104⁰C
Chiral rotation [α]_D	48°
Hazards
MSDS	External MSDS
Main hazards	Irritant,Flammable
Supplementary data page
Structure and properties	n, ε_r, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Hydrogen Bond Donor Count
Hydrogen Bond Acceptor Count
Spectral data	UV, IR, NMR, MS
Related compounds
Other anions	{{{Other_anion}}}
Other cations	{{{Ohter_cation}}}
Related compounds	{{{Relative_Compounds}}}
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Structure
Molecular shape	{{{MolShape}}}
Coordination geometry	{{{Coordination}}}
Crystal structure	{{{CrystalStruct}}}
Dipole moment	{{{Dipole}}} D

Menthol

Menthol is the chemical responsible for giving peppermints (and mint it's self) their cool sensation. It has the chemical formula C₁₀H₂₀O and has a crystalline structure.

Synthesis

The synthesis of synthesis of a racemic mixture of (S)-menthol (shown above) and (R)-menthol was devised by Hueckel and Bretschneider and published in 1938¹. Ethyl sodium, cyclohexane and ethyl-((1R)menthyl)-ether were used as the starting materials, yielding racemic menthol with ethane and 2-ethyl-1-isopropyl-4-methyl-cyclohexane as side products. A newly devised mechanism (winning the Nobel Prize in 2001!), to obtain optically pure (-)-menthol is shown below, using a chiral catalyst. ²

Stereoisomers

In addition to natural (-)menthol which is primarily produced by biosynthesis in nature, there are 7 other stereoisomers of the molecule, as shown below.