Natural acetylenes. Part XXIII. A C18 polyacetylenic keto-aldehyde related to falcarinone from an Umbellifer (Pastinaca sativa L.)
Abstract
The structure of the polyacetylenic keto-aldehyde {H2CCH·CO·[CC]2·CH2·CH[graphic omitted]CH·[CH2]7·CHO} has been determined. It is the first C18 polyacetylene to be isolated from a plant (Pastinaca sativa L.) of the main polyacetylene-producing families. Its occurrence almost certainly establishes the derivation of the C17 falcarinone and related compounds and is in harmony with Bu'Lock's hypothesis for the biogenesis of the natural acetylenes.