Longifolene is a commonsesquiterpene. It is an oily liquidhydrocarbon found primarily in the high-boiling fraction of certain pineresins. The name is derived from that of apine species from which the compound was isolated.[1] It is a tricyclic chiral molecule. Theenantiomer commonly found in pines and other higher plants exhibits a positiveoptical rotation of +42.73°. The other enantiomer (optical rotation −42.73°) is found in small amounts in certainfungi andliverworts.
The biosynthesis of longifolene begins withfarnesyl diphosphate (1) (also calledfarnesyl pyrophosphate) by means of a cationic polycyclization cascade. Loss of the pyrophosphate group and cyclization by the distalalkene gives intermediate3, which by means of a1,3-hydride shift gives intermediate4. After two additional cyclizations, intermediate6 produces longifolene by a1,2-alkyl migration.
^Naffa, P.; Ourisson, G.Bulletin de la Société chimique de France,1954, 1410.
^Corey, E. J.; Ohno, Masaji.; Mitra, Rajat B.; Vatakencherry, Paul A. (February 1964). "Total Synthesis of Longifolene".Journal of the American Chemical Society.86 (3):478–485.Bibcode:1964JAChS..86..478C.doi:10.1021/ja01057a039.
^McMurry, John E.; Isser, Stephen J. (October 1972). "Total synthesis of longifolene".Journal of the American Chemical Society.94 (20):7132–7137.Bibcode:1972JAChS..94.7132M.doi:10.1021/ja00775a044.
^Volkmann, Robert A.; Andrews, Glenn C.; Johnson, William S. (August 1975). "Novel Synthesis of Longifolene".Journal of the American Chemical Society.97 (16):4777–4779.Bibcode:1975JAChS..97.4777V.doi:10.1021/ja00849a062.
^Oppolzer, Wolfgang; Godel, Thierry (April 1978). "A New and Efficient Total Synthesis of (.+-.)-longifolene".Journal of the American Chemical Society.100 (8):2583–2584.Bibcode:1978JAChS.100.2583O.doi:10.1021/ja00476a071.
^Schultz, Arthur G.; Puig, Salvador (March 1985). "The Intramolecular Diene-Carbene Cycloaddition Equivalence and an Enantioselective Birch Reduction-Alkylation by the Chiral Auxiliary Approach. Total Synthesis of (.+-.)- and (−)-Longifolene".The Journal of Organic Chemistry.50 (6):915–916.doi:10.1021/jo00206a049.
^Bo, Lei; Fallis, Alex G. (May 1990). "Direct total synthesis of (+)-longifolene via an intramolecular Diels-Alder strategy".Journal of the American Chemical Society.112 (11):4609–4610.Bibcode:1990JAChS.112.4609B.doi:10.1021/ja00167a105.
^Dev, Sukh (1981). "Aspects of Longifolene chemistry. An example of another Facet of natural products chemistry".Accounts of Chemical Research.14 (3):82–88.doi:10.1021/ar00063a004.
