B. A. Bierl

Sex Attractant Pheromone of the House Fly: Isolation, Identification and Synthesis

A sex pheromone isolated from the cuticle and feces of the female house fly attracts the male fly; it has been identified as (Z)-9-tricosene. Chemical and biological comparisons of the natural and synthesized compounds show that they are identical.

Potent Sex Attractant of the Gypsy Moth: Its Isolation, Identification, and Synthesis

The sex attractant emitted by the female gypsy moth has been identified as cis-7,8-epoxy-2-methyloctadecane. The structure was verified by spectral, gas chromatographic, and biological comparisons with the synthesized compound. Nine closely related isomers were considerably less effective.

Host-Seeking Stimulant for Parasite of Corn Earworm: Isolation, Identification, and Synthesis

13-Methylhentriacontane has been identified in the feces and larvae of the corn earworm, Heliothis zea (Boddie), as the major constituent that triggers the short-range host-seeking response of the parasite Microplitis croceipes (Cresson). This chemical, the first found that mediates the complex host-parasite relation, could upgrade present efforts to use parasites for insect control. Bioassay of closely related compounds indicated that the structural requirements for activity are remarkably specific.

Sex Pheromones: (E,E)-8,10-Dodecadien-1-ol in the Codling Moth

Although (E,E)-8,10-Dodecadien-l-ol was reported to be a sex pheromone of the codling moth [Laspeyresia pomonella (L.)], its presence in the moth was questioned, mainly because it has not been isolated. A computerized search of data from gas chromatography-mass spectrometry of a partially purified extract equivalent to 45 abdominal tips of female moths produced a mass spectrum that matched that of the authentic coinpound. Other data also confirmed the presence of the compound.

Reaction loops for reaction Gas chromatography. Subtraction of alcohols, aldehydes, ketones, epoxides, and acids and carbon-skeleton vchromatography of polar compounds

SummaryReaction loops may be used in a gas Chromatographic system to help determine the chemical structure of compounds. Loops that retain or detain compounds with a certain functional group “subtract” these compounds and thereby indicate the presence of the functional group in unknown compounds. The performance of loops in “subtracting” alcohols, acids, aldehydes, ketones, epoxides, and a variety of other compounds was studied to amplify the usefulness of this technique. A simplified version of carbon-skeleton chromatography was also shown to be useful for analysis of polar or high molecular weight compounds (C12 or higher).ZusammenfassungReaktionsschleifen können sich in gaschromatographischen Geräten für die Ermittlung der chemischen Struktur von Verbindungen als nützlich erweisen. In diesen Schleifen werden Verbindungen mit einer bestimmten funktionellen Gruppe zurückgehalten, deren Vorhandensein in unbekannten Verbindungen damit indiziert wird. Die Wirkungsweise solcher Schleifen bei der Entfernung von Alkoholen, Säuren, Aldehyden, Ketonen, Epoxiden und verschiedenen anderen Verbindungen wurde studiert, um die Brauchbarkeit dieser Methodik zu erweitern. Eine einfachere Form der Kohlenwasserstoff-Chromatographie hat sich gleichfalls als wertvoll für die Analyse polarer oder Verbindungen mit hohem Molekulargewicht (C12 oder höher) erwiesen.

Ozone generator for microanalysis.

SummaryA small ozone generator useful for locating double bonds inμg amounts of organic compounds is easily constructed from an inexpensive vacuum tester. The unit is also useful for micro-preparative purposes.ZusammenfassungEin kleiner Ozonisator für die Ortsbestimmung von Doppelbindungen in Mikrogrammengen organischer Substanzen wurde aus einem billigen Vakuumprüfgerät hergestellt. Er eignet sich auch für mikropräparative Zwecke.

The Presence of Disparlure, the Sex Pheromone of the Gypsy Moth, in the Female Nun Moth

Disparlure, (cis-7,8-epoxy-2-methyloctadecane) the sex attractant of the gypsy moth, Porthetria (Lymantria) dispar, attracts the male nun moth, Lymantria monacha, in the field and is a highly effective olfactory stimulus in electroantennogram (EAG) and single-cell recordings. We have now analyzed the extract of 2000 abdominal tips of the female nun moth. Physical and chemical tests, which included gas-chromatographic retention times, elution volumes from silica gel and silica gel-silver nitrate columns, mass spectra, epoxide functionality, EAG-activity of chromatographic fractions with gypsy moth antennae, presence of disparlure precursor, all indicated that disparlure is present in the extract of nun moth sex glands. The optical activity of the natural disparlure of the two species has not yet been determined. Several authors have reported 1-0 that disparlure,

Electron-impact mass spectrometry for location of epoxide position in long chainvic-dialkyl and trialkyl epoxides

Plots of percent abundance vs m/e for selected series of ions (differing by 14 mass units) obtained by low resolution mass spectrometry allowed the epoxide position to be located in 30 C17−C21vic-dialkyl and trialkyl epoxides. Major diagnostic fragmentations are as follows. In thevic-dialkyl epoxides of the study, fragments useful for determining epoxide position result from α-cleavage, and epoxide position may be recognized by the maxima obtained in a plot of percent abundance vs m/e values in the CnH2n−1O series (113, 127, 141 ....); a similar plot of percent abundances vs m/e values in the CnH2n−2 series (110, 124, 138 ....) also shows maxima for ions corresponding to those obtained by transannular cleavage plus water elimination. In the trialkyl epoxides, fragments most useful for locating epoxide position are those obtained from ions corresponding to α-cleavage plus H-transfer; epoxide position may, thus, be recognized by the maxima obtained in a plot of percent abundance vs m/e values in the CnH2nO series (72, 86, 100 ....). Transannular cleavage with H-transfer produces CnH2n+1O products (m/e 115, 129, 143....), with the fragment containing the methyl substituent being much more abundant.

Di-2-ethylhexyl phthalate in thermally oxidized corn oil

A phthalate ester, recently isolated from thermally oxidized corn oil, has been identified as di-2-ethelhexyl phthalate.

Effects of hexamethylphosphoric triamide (hempa) upon allylic grignard reagents: Synthesis of long chain alkenol acetates

E or Z allylic Grignard reagents reacted with allylic halides in tetrahydrofuran-Hempa to give products in which the double bond from the organometallic fragment was predominantly Z. Protonation of the allylic Grignard reagents gave an increased proportion of Δ2-alkene and a higher ratio of Z:E isomers when Hempa was added.