Natural Occurrence
Before adamantane was synthesized, it was isolated from petroleum by Czech chemists S. Landa and V. Machacek in 1933. They used fractional distillation where a sample of petroleum was gradually heated until leaving only solid impurities. The resulting steam enters a fractional distillation column. The temperature of the column decreases as the steam rises through the column. Therefore, hydrocarbon fractions condense along the column corresponding to their boiling point. Landa and Machacek could produce only a few milligrams of adamantane but noticed its high boiling and melting points. Because of the (assumed) similarity of its structure to that of diamond, the new compound was named adamantane.
Petroleum remains the only natural source of adamantane; the content varies between 0.0001 and 0.03% depending on the oil field and is too low for commercial production.
Beside adamantane, petroleum contains more than thirty of its derivatives. Their isolation from a complex mixture of hydrocarbons is possible due to their high melting point and the ability to distill with water vapor and form stable adducts with thiourea.
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