Hajime Kaneko

Polyene Cyclization Terminated by Thiol.

Etude de la cyclisation acide stereoselective de dimethyl-4,8 nonadiene-3,7thiol-1 et de dimethyl-5,9 decadiene-4,8thiol-2 en trimethyl-4,4,7a- et tetramethyl-2,4,4,7a perhydro benzo [b] thiophenes

Nicotiana tabacum cv. Burley

Many acyclic terpenoids such as neophytadiene (1),1) phytofuran,2) farnesylacetone) and hexahydrofarnesyl-· acetone ) have been reported as aroma constituents of tobacco and of these compounds the diterpenoid hydrocarbon, neophytadiene (1), is well known to be by far the major neutral volatile constituent of tobacco. We report here the isolation of a new acyclic diterpenoid hydrocarbon, 7,11, 15-trimethyl-3-methylene-l ,6, 10, 14hexadecatetraene (3), which has been tentatively named geranylgeraniadiene, being structually-related to neophytadiene (1), from the neutral volatiles of Burley tobacco (Nicotiana tabacum). The structure of geranylgeraniadiene (3) corresponds to that of the dehydrated compound from geranylgeraniol (4).

Solanascone: a novel sesquiterpene ketone from Nicotiana tabacum. X-Ray structure determination of the corresponding oxime

Solanascone (1), a new tetracyclic sesquiterpene ketone, has been isolated from Nicotiana tabacum cv. Burley; its structure was confirmed by X-ray analysis of its corresponding oxime (2).

Studies on the Chemical Constituents of Tobacco Leaves: Part III. Isolation of (−)-2-Isopropyl-5-oxohexanoic Acid from Turkish Tobacco Leaves and Absolute Configuration of Solanone

S-(−)-2-Isopropyl-5-oxohexanoic acid was isolated from the ether extract of Turkish tobacco leaves. Since 2-isopropyl-5-oxohexanoic acid obtained by ozonolysis of (+)-solanone was leavorotatory, tobacco-derived solanone has R-configuration and might be a precursor of the acid in tobacco leaves.