The Molecular Structure of Vitamin A (CAS NO.68-26-8):

Empirical Formula: C₂₀H₃₀O
Molecular Weight: 286.4516 
IUPAC Name: (2E,4E,6E,8E)-3,7-Dimethyl-9-(2,6,6-trimethylcyclohexen-1-yl)nona-2,4,6,8-tetraen-1-ol 
Appearance: Yellow-Orange Powder
Product Categories: Intermediates & Fine Chemicals;Pharmaceuticals;Retinoids;Intracellular receptor
Nominal Mass: 286
Average Mass: 286.4516 
Monoisotopic Mass: 286.229666
Index of Refraction: 1.549
Molar Refractivity: 95.49 cm³
Molar Volume: 300 cm³
Surface Tension: 36.6 dyne/cm
Density: 0.954 g/cm³
Flash Point: 147.3 °C
Enthalpy of Vaporization: 77.99 kJ/mol
Boiling Point: 421.2 °C at 760 mmHg
Vapour Pressure: 7.35E-09 mmHg at 25°C 
Stability: Stable, but light and air sensitive. Incompatible with strong acids, strong oxidizing agents
InChI: InChI=1/C20H30O/c1-16(8-6-9-17(2)13-15-21)11-12-19-18(3)10-7-14-20(19,4)5/h6,8-9,11-13,21H,7,10,14-15H2,1-5H3/b9-6+,12-11+,16-8+,17-13+
Smiles: C=1(C(CCCC1C)(C)C)\C=C\C(=C\C=C\C(=C\CO)C)C 
Melting Point: 63.5 °C
log P (octanol-water): 5.68  
Water Solubility: 0.671 mg/L at 25 °C 
Henry's Law Constant: 1.16E-04 atm-m³/mole at 25 °C 
Atmospheric OH Rate Constant: 4.00E-10 cm³/molecule-sec at 25 °C 

  Vitamin A (CAS NO.68-26-8) was first synthesized in 1947 by two Dutch chemists, David Adriaan van Dorp and Jozef Ferdinand Arens. The discovery of vitamin A may have stemmed from research dating back to 1906, indicating that factors other than carbohydrates, proteins, and fats were necessary to keep cattle healthy.By 1917 one of these substances was independently discovered by Elmer McCollum at the University of Wisconsin-Madison, and Lafayette Mendel and Thomas Burr Osborne at Yale University. Since "water-soluble factor B" ( Vitamin B ) had recently been discovered, the researchers chose the name "fat-soluble factor A" (vitamin A).

 Vitamin A (CAS NO.68-26-8) is important in vision and bone growth,and appears to function in maintaining normal skin health.It is used in medicine and feed industry.

Reported in EPA TSCA Inventory. EPA Genetic Toxicology Program.

Moderately toxic by ingestion. Human teratogenic effects by ingestion: developmental abnormalities of the craniofacial area and urogenital system. An experimental teratogen. Experimental reproductive effects. Human mutation data reported. When heated to decomposition it emits acrid smoke and irritating fumes.
Hazard Codes: XnNF
Risk Statements: 22-38-67-65-62-51/53-48/20-11 
R22: Harmful if swallowed
R38: Irritating to skin
R67: Vapours may cause drowsiness and dizziness
R65: Harmful: may cause lung damage if swallowed
R62: Risk of impaired fertility
R51/53: Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment
R48/20: Harmful: danger of serious damage to health by prolonged exposure through inhalation
R11: Highly flammable
Safety Statements: 36/37-61-62 
S36/37: Wear suitable protective clothing and gloves
S61: Avoid release to the environment. Refer to special instructions / safety data sheets
S62: If swallowed, do not induce vomitting; seek medical advice immediately and show this container or label
RIDADR: UN 1208 3/PG 2
WGK Germany: 3
RTECS: VH6750000
F: 8-10-16-23 
F 8: Photosensitive
F 10: Keep under argon
F 16: Decomposes easily
F 23: Sensitive to air

 Vitamin A (CAS NO.68-26-8) is also called as Retinol [INN:BAN] ; (all-E)-3,7-Dimethyl-9-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4,6,8-nonatetraen-1-ol ; 2,4,6,8-Nonatetraen-1-ol, 3,7-dimethyl-9-(2,6,6-trimethyl-1-cyclohexen-1-yl)-, (all-E)- ; 3,7-Dimethyl-9-(2,6,6-trimethyl-1-cyclchexen-1-yl)-2,4,6,8-nonatetraen-1-ol ; 3,7-Dimethyl-9-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4,6,8-nonatetraen-1-ol, (all-E)- ; A-Mulsal ; A-Sol ; A-Vi-Pel ; A-Vitan ; ACON ; ATAV ; Afaxin ; Agiolan ; Agoncal ; Alcovit A ; All-trans retinol ; Alphalin ; Alphasterol ; Anatola ; Anatola A ; Anti-infective vitamin ; Antixerophthalmic vitamin ; Antixerophthalmisches Vitamin ; Aoral ; Apexol ; Apostavit ; Aquasol A ; Aquasynth ; Atars ; Avibon ; Avita ; Avitol ; Axerol ; Axerophthol ; Axerophtholum ; BRN 0403040 ; Bentavit A ; Biosterol ; Chocola A ; Del-VI-A ; Disatabs Tabs ; Dofsol ; Dohyfral A ; EINECS 200-683-7 ; Epiteliol ; HI-A-Vita ; HSDB 815 ; Homagenets Aoral ; Lard factor ; Myvpack ; NSC 122759 ; Nio-A-let ; Oleovitamin A ; Ophthalamin ; Plivit A ; Prepalin ; Retinol ; Retinol, all trans- ; Retinolo ; Retinolo [DCIT] ; Retinolum ; Retinolum [INN-Latin] ; Retrovitamin A ; Sehkraft A ; Solu-A ; Super A ; Testavol ; Testavol S ; UNII-81G40H8B0T ; UNII-G2SH0XKK91 ; VI-alpha ; Vaflol ; Vafol ; Veroftal ; Vi-Dom-A ; Vi-alpha ; Vi-alpha; Vi-alpha ; Vio-A ; Vitamin A alcohol (VAN) ; Vitamin A alcohol, all-trans- ; Vitamin A1 ; Vitamin A1 alcohol ; Vitamin A1 alcohol, all trans ; Vitamin A1, all-trans- ; Wachstumsvitamin ; all-trans-Retinol ; all-trans-Retinyl alcohol ; all-trans-Vitamin A ; all-trans-Vitamin A alcohol ; 3,7-Dimethyl-9-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4,6,8-nonate-traen-1-ol ; Alcohol 9,13-dimethyl-7-(1,1,5-trimethyl-6-cyclohexen-5-yl)-7,9,11,13-nonatetraen-15-ol  .