Pheromone, XXXII. Bausteine zur Darstellung zweifach ungesättigter Schmetterlings-pheromone
作者:Hans Jürgen Bestmann、Karl Heinrich Koschatzky、Wilfried Schätzke、Joachim Süß、Otto Vostrowsky
DOI:10.1002/jlac.198119810920
日期:1981.9.21
Die Darstellung α,ω-bifunktioneller Ausgangsverbindungen sowie (Z)- und (E)-konfigurierter, ungesättigter Synthesebausteine, die man mittels Wittig-Reaktion, Michael-Addition, Acetylen-synthese oder Crombie-Reaktion erhält, wird beschrieben. Diese Verbindungen werden im Rahmen eines „Baukastensystems” zur Synthese bisolefinischer Sexualpheromone benötigt.
The stericcourse of some reactions of 2,3-dihalotetrahydropyrans with sodium methoxide and with methyl- and phenyl-magnesium bromides has been reinvestigated. Whereas the methanolysis of the - and -dichlorides occurs with practically complete inversion, it has been confirmed that their reactions, as well as those of the dibromides, with methyl-magnesium bromide are non-stereospecific, yielding mixtures
Pheromone XLI. Stereoselektive Synthesen von 1,5- und 1,6-Alkadienen als Sexualpheromone und Pheromonanaloge
作者:Hans Jürgen Bestmann、Karl Heinrich Koschatzky、Otto Vostrowsky
DOI:10.1002/jlac.198219820807
日期:1982.8.19
Nach Art eines „Baukastensystems” werden Alkadienylacetate, Alkadienole und Alkadienale, wie sie alsSexualpheromone weiblicher Schmetterlinge bekannt sind, mit ethylen- bzw. trimethylenunterbrochenen Doppelbindungen (1,5- bzw. 1,6-Alkadiene) unterschiedlicher Positionen und Geometrien synthetisiert.
Dithiolopyranthione Synthesis, Spectroscopy, and an Unusual Reactivity with DDQ
作者:Igor V. Pimkov、Archana Nigam、Kiran Venna、Fraser F. Fleming、Pavlo V. Solntsev、Victor N. Nemykin、Partha Basu
DOI:10.1002/jhet.1715
日期:2013.7
The bicyclic pyran thiolone tetrahydro‐3αH‐[1,3]dithiolo[4,5‐β]pyran‐2‐thione (3a) engages in a highly unusual fragmentation in the presence of DDQ. The pyran thiolone, 3a, was synthesized by chlorination of 3,4‐dihydro‐2H‐pyran (1) followed by condensing with CS2 and NaSH. Reaction of 3a with DDQ generates the isomerized pyran thiolone tetrahydro‐3αH‐[1,3]dithiolo[4,5‐β]pyran‐2‐thione (3b) and 4‐b
THE MECHANISMS OF THE HALOGENATIONS AND HALOGENOMETHOXYLATIONS OF <scp>D</scp>-GLUCAL TRIACETATE, <scp>D</scp>-GALACTAL TRIACETATE, AND 3,4-DIHYDROPYRAN
作者:R. U. Lemieux、B. Fraser-Reid
DOI:10.1139/v65-197
日期:1965.5.1
when the halogen, the olefin, and the solvent were changed, which can be accounted for on the basis of (a) the relative stabilities of the halonium and oxocarbonium ions formed as intermediates, (b) the effect of ring conformation on the ease of formation of oxocarbonium ions involving the ring-oxygen of the pyranose ring, (c) the role of the anomericeffect in determining the stability of the transition