- L-(-)-menthol in the synthesis of key synthons for optically active methyl-branched insect pheromones
-
A synthesis of optically active 4S-methylhexanal, 1-bromo-3S-methylheptane, and 1-bromo-3S-methylundecane, which are key synthons for several methyl-branched insect pheromones, that is based on chemically selective transformations of 6-tosyloxy- and 6-iodoisopropyl-4R-methylhexanoates that are available from L-(-)-menthol was proposed. 2005 Springer Science+Business Media, Inc.
- Ishmuratov,Yakovleva,Ganieva,Amirkhanov,Tolstikov
-
-
Read Online
- (3S,5R)-6-(benzyloxy)-3-methylhexane-1,5-diol in the synthesis of insect pheromones with methyl-branched carbon chain and of amphidinolide L C 7 -C 14 fragment
-
New building block (3S,5R)-6-(benzyloxy)-3-methylhexane-1,5-diol was obtained, and based thereon new formal syntheses of (Z)-trogodermal, a component of the sex pheromone of smaller tea tortrix and of the alarm pheromone of ants of genus Crematogaster were suggested. A new synthetic protocol for (3S)-5-methyl-5-oxopentyl acetate and (3S)-5-(benzyloxy)-3-methylpentanal, convenient building blocks for insect pheromones designing was developed. A new simple and efficient asymmetric synthesis of C7-C14 fragment of the cytotoxic macrolactone amphidinolide L was carried out.
- Mineeva
-
p. 168 - 174
(2014/04/17)
-
- Novel Caprolactones from a Marine Streptomycete
-
Two new caprolactones, (R)-10-methyl-6-undecanolide (1) and (6R,10S)-10-methyl-6-dodecanolide (2), were identified in the lipid extract of a marine streptomycete (isolate B6007). Their structures were proposed on the basis of GC-MS experiments and proved by synthesis. The absolute configuration of the compounds was established by comparison of the natural and synthetic stereoisomers using chiral gas chromatography. These caprolactones show a moderate phytotoxicity and a promising activity against cancer cells with concomitant low general cytotoxicity.
- Stritzke, Katja,Schulz, Stefan,Laatsch, Hartmut,Helmke, Elisabeth,Beil, Winfried
-
p. 395 - 401
(2007/10/03)
-
- Syntheses of the sixteen stereoisomers of 3,7,11-trimethyl-2-tridecanol, including the (2S,3S,7S,11R) and (2S,3S,7S,11S) stereoisomers identified as pheromone precursors in females of the pine sawfly Microdiprion pallipes (Hymenoptera: Diprionidae)
-
All sixteen stereoisomers of 3,7,11-trimethyl-2-tridecanol were synthesised in high stereoisomerical purities (> 95%), for use in the identification of the stereoisomers present in females of the pine sawfly Microdiprion pallipes (Fallén) (Hymenoptera: Diprionidae) as the precursor of the actual sex pheromone (which is the propionate), and also for investigation of the biological activities of the esters. The key step in the syntheses was the coupling of each of the enantiomers of cis-3,4-dimethyl-γ-butyrolactone with each of the four pure stereoisomers of 1-lithio-2,6-dimethyloctanes. The four corresponding alcohols were obtained by lipase-catalysed (Amano PS) kinetic separation, based on selective acylation of either (2R/S,6S)- or (2R/S,6R)-2,6-dimethyl-1-octanol (obtained from the optically pure enantiomers of citronellal). Additionally, a mixture of the 16 possible stereoisomers of 3,7,11-trimethyl-2-tridecanol was also prepared. Wiley-VCH Verlag GmbH, 2001.
- Larsson, Michael,Nguyen, Ba-Vu,H?gberg, Hans-Erik,Hedenstr?m, Erik
-
p. 353 - 363
(2007/10/03)
-
- Highly regio-, (E)-stereo-, and diastereoselective SN2′ addition of organocuprates to chiral allylic cyclic carbonates
-
Reaction of the cyclic carbonates of acyclic vinyl diols with RCu(CN)Li· BF3, RCu(CN)MgBr·BF3, or RMgBr·CuI (cat) in THF at -78°C proceeded in SN2′ fashion and resulted in the formation of alkylated (E)-allylic alcohols wi
- Kang, Suk-Ku,Lee, Dong-Ha,Sim, Hyeong-Su,Lim, Jong-Suk
-
-
- 48. Ferroelectric Liquid Crystals Part 2 Chiral Phenyl Benzoates Incorporating a trans-1,4-Disubstituted Cyclohexane Ring
-
About forty novel phenyl benzoates also incorporating a trans-1,4-disubstituted cyclohexane ring and a chiral centre have been prepared.The dependence of the liquid-crystal transition temperatures of this new class of compounds on lateral substituents, diverse central linkages, chain lengths, and position of the chiral centre has been studied systematically.The synthesis and liquid-crystal transition temperatures of these new compounds are described in detail.
- Kelly, Stephen M.,Buchecker, Richard
-
p. 451 - 460
(2007/10/02)
-
- SYNTHESIS AND MESOMORPHYSM OF SOME NEW FERRO-ELECTRIC SMECTIC LIQUID CRYSTALS
-
In this work, compounds having the general formula: (I) (II) with (X=H, Br, CN, Cl) and (R1 (or/and) R2=3-methyl-hexyl or 2-methyl-butyl, n-alkyl were prepared and their phase transition temperatures and mesomorphic properties determin
- Decobert, Guy,Dubois, Jean-Claude
-
p. 237 - 248
(2007/10/02)
-
- A PURE DISC-LIKE MOLECULE WITH CHOLESTERIC PROPERTIES
-
A cholesterogenic disc-like derivative of triphenylene is described.The ND* phase exhibits oily streaks from 192.5 to 246.5 deg C.That is the first evidence of a cholesteric phase in a pure disc-like molecule.
- Malthete, J.,Destrade, C.,Tinh, Nguyen Huu,Jacques, J.
-
p. 233 - 238
(2007/10/02)
-
