There are two major sources of organic compounds.
1) Natural Sources
a) Plants:- carbohydrates (Glucose, sucrose, starch, cellulose), acids, esters, vegetable oils, vitamins, gums, alkaloids, essential oils, perfumes, alcohol, acetone, etc., are some of the important organic compounds which are obtained from plants.
b) Animals: - some of the important organic compounds, which are derived from animals, are proteins, hormones, fats and urea.
c) Fungi and micro organism: - this is the source responsible for the production of hosts of useful substances like alcohols, acids, antibiotics (penicillin, streptomycin, and tetracycline) and vitamins by using the process of fermentation.
d) Coal: - Coal-tar obtained during destructive distillation of coal is the main source of aromatic hydrocarbons, phenols, heterocyclic compounds, dyes, drugs, perfumes, etc.
e) Natural gas and petroleum:- it is one of the major source of organic compounds. Gasolines, kerosene oil, lubricating oil, Vaseline, paraffin wax, etc., are few examples which are obtained directly from petroleum by fractional distillation. Hundreds of useful organic compounds are prepared from the wide range of hydrocarbons which serve starting materials for the synthetic reactions.
Synthetic Sources: - More than 90% of the known organic compounds are synthetic, i.e., prepared by artificial methods. Simple organic compounds derived from petroleum and coal has been converted into useful products by synthetic methods. Now-a-days, many of the natural products such as dyes, fibers, rubber, drugs, vitamins, etc., are prepared by synthetic reactions.