Stereoisomeric Analysis of 6,10,14-Trimethylpentadecan-2-ol and the Corresponding Ketone in Wing Extracts from African Bicyclus Butterfly Species
Gas chromatography (GC) and mass spectrometry (MS) were used to determine the stereoisomeric compositions of 6,10,14-trimethylpentadecan-2-ol and 6,10,14-trimethylpentadecan-2-one in wing extracts from 17 Bicyclus butterfly species from different regions of Africa. All samples were purified using solid phase extraction (SPE). Since some species contained both alcohol and ketone, these were separated and the ketone was reduced to the alcohol before analysis as either (R)-trans-chrysanthemoyl or (S)-2-acetoxypropionyl esters. A novel asymmetric synthesis was developed for a reference mixture of (2R/S,6S,10R)-6,10,14-trimethylpentadecan-2-ol with known composition of the eight stereoisomers. The mixture then was used as the (R)-trans-chrysanthemoyl esters to correlate each of the eight gas chromatographic peaks to a specific stereoisomer of the extracted wing compounds. Seven butterfly species showed (2R,6R,10R)-configuration of the alcohol, four species contained minute amounts of alcohol too small to determine the stereochemistry, nine species showed (6R,10R)-configuration of the ketone, and one species contained minute amounts of ketone too small to determine the stereochemistry. No other stereoisomers of alcohol or ketone could be detected in the extracts, and the quantities of the compounds in the wing extracts varied from 5 to 900 ng per sample for each species.
Enantioselective Synthesis Of (S)-2-Methyl-1-Alkanols Via Bakers-Yeast Mediated Reduction Of Alpha-Methyl-2-Thiophenepropenals
Enantioselective Synthesis Of (S)-2-Methyl-1-Alkanols Via Bakers-Yeast Mediated Reduction Of Alpha-Methyl-2-Thiophenepropenals
Collection of Additional Sex Attractant from the Virgin Female Introduced Pine Sawfly
Additional sex attractant material was obtained from virgin females of the introduced pine sawfly, Diprion similis (Hartig), by trapping the volatile fraction. Though amounts were small, activity of males in field bioassays indicated attractancy with as little as 3 sawfly-equivalenthours before purification. Details of the trapping apparatus are provided.