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Keywords
- Oxygen heterocycles (2)
- C-C coupling (1)
- Diazonium salts (1)
- Furans (1)
- Heck coupling (1)
- Lactones (1)
- Metalation (1)
- Metathesis (1)
- Oxidation (1)
- Palladium (1)
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Rezensiertes Werk: Wirtschaft und Kultur im Transformationsprozeß : Wirkungen, Interdependenzen, Konflikte / Hans-Hermann Höhmann (Hg.). [Forschungsstelle Osteuropa an der Universität Bremen]. - Bremen : Ed. Temmen, 2002. - 297 S. - (Analysen zur Kultur und Gesellschaft im östlichen Europa ; Bd. 11) ISBN 3-86108-340-X
Rezensiertes Werk: Kommerz, Kunst, Unterhaltung : die neue Popularkultur in Zentral- und Osteuropa / Forschungsstelle Osteuropa an der Universität Bremen (Hg.). Konzeption und Red.: Ivo Bock ... - Bremen : Ed. Temmen, 2002. - 339 S. - (Analysen zur Kultur und Gesellschaft im östlichen Europa ; Bd. 13) ISBN 3-86108-345-0
Butenolides, obtained by ring-closing metathesis (RCM) of acrylates, undergo quantitative deprotonation with amide bases. Trapping of the resulting anions with electrophiles, for example, chlorophosphates, give furans. Subsequent DielsAlder reaction and acid-catalysed rearrangement of the resulting oxabicyclonorbornadienes give substituted benzenes.
2,5-Disubstituted furans were synthesized by one-flask Heck arylation/oxidation sequences. The starting materials are 2-substituted 2,3-dihydrofurans, conveniently available by RCM/isomerization sequences, and arenediazonium salts. These react in ligand-free Heck reactions to afford 2,5-disub-stituted 2,5-dihydrofurans, which are oxidized to the corresponding furans without isolation or intermediate workup. The oxidation is conveniently achieved with chloranil or DDQ, depending on the substrate.
To identify genetic variants associated with head circumference in infancy, we performed a meta-analysis of seven genome-wide association studies (GWAS) (N = 10,768 individuals of European ancestry enrolled in pregnancy and/or birth cohorts) and followed up three lead signals in six replication studies (combined N = 19,089). rs7980687 on chromosome 12q24 (P = 8.1 x 10(-9)) and rs1042725 on chromosome 12q15 (P = 2.8 x 10(-10)) were robustly associated with head circumference in infancy. Although these loci have previously been associated with adult height(1), their effects on infant head circumference were largely independent of height (P = 3.8 x 10(-7) for rs7980687 and P = 1.3 x 10(-7) for rs1042725 after adjustment for infant height). A third signal, rs11655470 on chromosome 17q21, showed suggestive evidence of association with head circumference (P = 3.9 x 10(-6)). SNPs correlated to the 17q21 signal have shown genome-wide association with adult intracranial volume(2), Parkinson's disease and other neurodegenerative diseases(3-5), indicating that a common genetic variant in this region might link early brain growth with neurological disease in later life.
(5R,6S)-6-Acetoxy-5-hexadecanolide (MOP) is the oviposition pheromone of the mosquito Cx. quinquefasciatus, a vector of pathogens causing a variety of tropical diseases. We describe and evaluate herein three syntheses of MOP starting from mannitol-derived (3R,4R)-hexa-1,5-diene-3,4-diol. This C-2-symmetric building block is elaborated through bidirectional olefin metathesis reactions into 6-epi-MOP, which was converted into MOP via Mitsunobu inversion. The shortest of the three routes makes use of two sequential cross-metathesis reactions and an assisted tandem catalytic olefin reduction, induced by an in situ conversion of a Ru-carbene to a Ru-hydride.