Geraniol | Uses, Structure, Preparation, & Properties |

Geraniol.

It is an acyclic terpene alcohol in addition to has the structure:

Geraniol occurs inwards oils of rose, palmrosa, geranium, citronella, lemongrass, in addition to lavender.

Preparation of Geraniol.

(1) From palmrosa Oil. This is obtained inexpensive from a wild-growing grass, cymbopogon Martini, past times steam distillation. When the fossil oil is treated alongside anhydrous calcium chloride, geraniol reacts alongside it to hand a crystalline add-on product. This is separated in addition to decomposed alongside H2O to release geraniol.

(2) From Citral-a. Geraniol may likewise hold out prepared past times reduction of citral-a (geraniol) alongside aluminium amalgam.

Physical Properties of Geraniol.

Geraniol is a colourless liquid, bp 230ºC, having pleasant rose-like odour. It is insoluble inwards H2O exactly dissolves inwards ethanol.

Geraniol exhibits geometrical isomerism in addition to it is cis-form. The trans-isomer is to a greater extent than or less other terpene Nerol (from neroli oil), colourless liquid, bp 225ºC, having rose-like odour.

Chemical Properties of Geraniol.

The structural formula of geraniol has 2 carbon-carbon double bonds in addition to a principal alcohol group. Thus it gives the reactions of dienes every bit likewise of principal alcohols. Two of its of import reactions are listed below.

(1) Oxidation. Upon oxidation, geraniol is rootage converted citral-a and thus to geranic acid.

(2) Cyclization.When treated alongside dilute sulphuric acid, geraniol forms α-terpineol.

Uses of Geraniol.

Geraniol in addition to nerol are extensively used inwards perfumery to get the olfactory belongings of roses.

Geraniol Structure.

Geraniol has the molecular formula C10H18O.

Presence of 2 C=C bonds. It adds 2 molecular of bromine, in addition to 2 molecules of hydrogen on catalytic hydrogenation, showing the presence of 2 carbon-carbon double bonds.

Presence of CH2OH. On oxidation it gives an aldehyde (citral-a) in addition to thus an acid (geranic acid) containing the same publish of carbon atoms every bit geraniol.

This proves that geraniol is a principal alcohol in addition to the arrangment of C atoms every bit likewise the positions of the 2 double bonds are the same every bit inwards Citral-a.
Structure derived from that of citral. Knowing the structural formula of citral-a, geraniol is assigned the structure.

Therefore, geraniol is likewise the cis-form which is confirmed past times NMR studies.