Chemical composition of fragrant materials. IV. A new keto-alcohol, (-)-mintlactone, (+)-isomintlactone and minor components in peppermint oil.

Eighty-one constituents were newly identified from the oil of Mentha piperita L ., including a new keto-alcohol, (-)-mintlactone and (+)-isomintlactone.They were determined by spectral data and syntheses to be 4-hydroxy-4-methyl-2-cyclohexen-l-one (8), (6R, 7aR) (10) and (6R, 7aS)-3,6-dimethyl-5,6,7,7a-tetrahydro-2(4H)-benzofuranone (11) , respectively.Part IV.Part III.Odorous Constituents of the Absolute from Flower of Citrus unshiu Marcovitch.