Chemistry of Fragrance

IngredientsDr. William L. Schreiber

Chemlumina LLCMonmouth University

Presented at Fairleigh Dickenson University

November 7, 2006

Dr. William L. SchreiberChemlumina LLC

Monmouth UniversityPresented at Fairleigh Dickenson

UniversityNovember 7, 2006

To be discussed

• What is a perfume?• History• Natural Ingredients• Synthetic Ingredients• Chemical Process Examples• Research on New

Synthetics• The Science of Olfaction

• What is a perfume?• History• Natural Ingredients• Synthetic Ingredients• Chemical Process Examples• Research on New

Synthetics• The Science of Olfaction

What Are Perfumes?

Mixtures that are created for use in a wide variety of applications:

expensive couturier perfumes, cosmetics, personal grooming products, laundry products, household cleaning products, air fresheners, candles, etc., etc., etc..

From a palette of several thousand materials, most of which are manufactured by chemical processing methods.

Mixtures that are created for use in a wide variety of applications:

expensive couturier perfumes, cosmetics, personal grooming products, laundry products, household cleaning products, air fresheners, candles, etc., etc., etc..

From a palette of several thousand materials, most of which are manufactured by chemical processing methods.

History of Perfumes5000 BC – Egyptian First Dynasty – earliest evidence

3000 BC – Mesopotamia: extraction pots, early apparatus

1400 BC – Book of Exodus “anointing with oils”

370 BCE – Theophrastus writings on use of oils to make fragrances longer lasting.

800 AD – Alembic distillation apparatus – Jabir ibn Hayyan

1200 AD – Essential oils produced in pharmacies

1600 AD – Quality of many natural extracts established

1860 AD – First synthetics (naturally occuring materials)

1900 AD – First non-natural synthetics (ionones, nitro-musks)

5000 BC – Egyptian First Dynasty – earliest evidence

3000 BC – Mesopotamia: extraction pots, early apparatus

1400 BC – Book of Exodus “anointing with oils”

370 BCE – Theophrastus writings on use of oils to make fragrances longer lasting.

800 AD – Alembic distillation apparatus – Jabir ibn Hayyan

1200 AD – Essential oils produced in pharmacies

1600 AD – Quality of many natural extracts established

1860 AD – First synthetics (naturally occuring materials)

1900 AD – First non-natural synthetics (ionones, nitro-musks)

Alembic Distillation Appratus

What are Fragrance Ingredients?

• Odorants, Diluents and Fixatives

• Naturals and Synthetics

• Chemicals having 6 – 18 carbon atoms (mostly), and usually one oxygenated functional group. There are also some multi-functional materials as well as a few sulfur- and nitrogen-containing chemical compound.

• Odorants, Diluents and Fixatives

• Naturals and Synthetics

• Chemicals having 6 – 18 carbon atoms (mostly), and usually one oxygenated functional group. There are also some multi-functional materials as well as a few sulfur- and nitrogen-containing chemical compound.

What are Fragrance Ingredients?R

OH

RCHO

R

O

R O

O

RO

O

alcohols

aldehydes

ketones

esters

RSH

OH

N

R

phenolics

olefins

mercaptans

amines

Performance in Use

• Volatility– Function of molecular weight (how

many carbons) and chemical type.

• Stability– Function of chemical type and use

condition (acidity, alkalinity, oxidizing, open, closed).

• Odor Threshold and dose/response– Function of chemical structure

(molecular shape and chemical type).

• Volatility– Function of molecular weight (how

many carbons) and chemical type.

• Stability– Function of chemical type and use

condition (acidity, alkalinity, oxidizing, open, closed).

• Odor Threshold and dose/response– Function of chemical structure

(molecular shape and chemical type).

Natural Ingredients

• Mostly of vegetative origin, a few from animal secretions – largely replaced.

• Any part of a plant may be used: flowers, fruits, leaves, twigs, roots, wood.

• Synthetics have long overtaken naturals in volume of use.

• Naturals still very valuable and provide odor reference points for all materials.

• Mostly of vegetative origin, a few from animal secretions – largely replaced.

• Any part of a plant may be used: flowers, fruits, leaves, twigs, roots, wood.

• Synthetics have long overtaken naturals in volume of use.

• Naturals still very valuable and provide odor reference points for all materials.

Types of Naturals

Concretes – extracts with solvent removed

Absolutes – concretes re-dissolved and filtered to remove waxes, etc.

Essential oils – distillates, often with steam

Concretes – extracts with solvent removed

Absolutes – concretes re-dissolved and filtered to remove waxes, etc.

Essential oils – distillates, often with steam

Narcisse Concrete

Rose

Most important constituents:Most important constituents:OH

OH

OOH

b-phenethyl alcohol

citronellollinalool

b-damascenone

Jasmine

Most important constituentsMost important constituents

O O

COOCH3

NH

cis-jasmone methyl jasmonate

indole

Patchouli

Most important constituents:

tricyclic sesquiterpene alcohols

Most important constituents:

tricyclic sesquiterpene alcohols

OH OH OH

Sandalwood

• Alpha Santalol:

• Beta Santalol:

• Alpha Santalol:

• Beta Santalol:

OH

OH

First Synthetics

OH

CH3O O

O O

vanillin coumarin

ONO2

O2N NO2

methyl ionone gamma musk xylol

Synthesis of Vanillin

OH

CH3O

OH

CH3O

OH

CH3O O

eugenol(from clove oil)

isoeugenol

OH-

CrVI or MnVII

Synthesis of Coumarin

CHO

OH O

O O

O O+ KOAc

(Perkin condensation)

salicylaldehydeaceticanhydride

Synthesis of Ionones

OO

O

O

+

citral 2-butanone

"gamma methyl ionone"

H3PO4

OH-

O

alpha-irone

Terpene Alcohols from -Pinene

Cl

OAcOHOH

OH-H2

3beta-pinene

myrcene

geranyl acetatecitronellol

HCl

sodiumacetate

Terpene Alcohols from -Pinene

OH

OOH

OH

OH

H2

H2

O2

3

linaloolgeraniol

alpha-pinene

More Products from -Pinene via Myrcene

CHOOH OH CHO

(acrolein)

Lyral

O O O

Iso E Super

H+

CHOO

+*Diels - Alder Reactions

*

*

Sandalwood “Molecular Engineering”

• Alpha Santalol:

• Beta Santalol:

• Alpha Santalol:

• Beta Santalol:

OH

OH

Synthetic Sandalwoods

OCHO

peraceticacid

ZnCl2campholenic aldehyde

alpha-pinene

O

OH

O

H2

Sandalore

CHO

O

OH

Bacdanol

Musks

O

O2N NO2

O

O

O

O

muscone muskalactone

musk ketone Galaxolide

Galaxolide Synthesis

OHO

O

H+

t-amylene a-methylstyrene

(CH2O)n, H+

(propylene oxide)

(paraformaldehyde)

Newer Musk Synthesis

OOH

O OH O

OOOH

OOOO

+

peroxidecatalyst

H+

Cucatalyst

H2

H2O2

GlobalideHabanolide

Muskalactone

cyclododecanone

allyl alcohol

Research and Development

• Analytical– Application of new gc methods (head space

with spme)– Use of more sensitive and better

computerized instrumentation: gc-ms, nmr, ft-ir.

• Live flowers – above methods used to analyze odors of flowers before picking.

• New extraction methods for naturals: supercritical CO2

• Analytical– Application of new gc methods (head space

with spme)– Use of more sensitive and better

computerized instrumentation: gc-ms, nmr, ft-ir.

• Live flowers – above methods used to analyze odors of flowers before picking.

• New extraction methods for naturals: supercritical CO2

Synthetic Research

Considerations:

• Structure – relationship to materials of known value – natural or synthetic

• Raw materials

• Process

(often a combination of all three)

Considerations:

• Structure – relationship to materials of known value – natural or synthetic

• Raw materials

• Process

(often a combination of all three)

Synthetic Research

Practical only for largest companies.

• Hundreds of materials synthesized each year for evaluation.

• In-depth evaluation must include testing in fragrances and in applications.

• Decision to develop cannot be taken lightly.

Practical only for largest companies.

• Hundreds of materials synthesized each year for evaluation.

• In-depth evaluation must include testing in fragrances and in applications.

• Decision to develop cannot be taken lightly.

Development of New Synthetics

• Processes must be very well worked out in laboratory, pilot plant and factory.

• Best economics, safety and workplace hygiene.

• Testing is required to meet industry safety standards and international PMN requirements for all new chemicals.

• Cost to register new ingredients worldwide is well over $300,000.

• Processes must be very well worked out in laboratory, pilot plant and factory.

• Best economics, safety and workplace hygiene.

• Testing is required to meet industry safety standards and international PMN requirements for all new chemicals.

• Cost to register new ingredients worldwide is well over $300,000.

How We Smell

Recent Developments• 1991 – Richard Axel and Linda Buck

discover a family of genes that appear to be responsible for olfactory receptors.

(received Nobel Prize – 2005)

• 1998 – Stuart Firestein expresses a receptor from one of those genes and shows it responds to different odorants.

• 2000 – Linda Buck shows that odor perception is based on combinatorial interaction of odorants with receptors.

• 1991 – Richard Axel and Linda Buck discover a family of genes that appear to be responsible for olfactory receptors.

(received Nobel Prize – 2005)

• 1998 – Stuart Firestein expresses a receptor from one of those genes and shows it responds to different odorants.

• 2000 – Linda Buck shows that odor perception is based on combinatorial interaction of odorants with receptors.

A Code in the Nose

Combinatorial Detection

350 Receptors: 2350 =2.3X10105 Combinations

= Unactivated = Activated

Od

ora

nts

Receptors1 2 3 4 5 6 7 8 9 10 ….

A B C D E F

In Conclusion…

• Fragrance ingredients are a complex part of a the even more complex world of perfumes. Understanding what they are, where they come from and what they do is the key to making better smelling and better performing fragrances.

• Fragrance ingredients are a complex part of a the even more complex world of perfumes. Understanding what they are, where they come from and what they do is the key to making better smelling and better performing fragrances.

Thank you for the opportunity to participate in your class this evening.