648434-47-3Relevant articles and documents
2-Isopropylbenzimidazole and 2-methylbenzimidazole as bulky proton sources: Stereoselective protonation and application to the synthesis of γ- and δ-lactones
Sengupta, Aakash,Hosokawa, Seijiro
, p. 411 - 414 (2019/01/05)
2-Isopropylbenzimidazole and 2-methylbenzimidazole have been found to be effective bulky proton sources for stereoselective protonation of chiral enolate anions. 2-Isopropylbenzimidazole worked in the stereoselective protonation of the Birch reduction of chiral α,β-unsaturated imides. On the other hand, 2-methylbenzimidazole was found to be the best protonation reagent in the isomerization reaction of α,β-unsaturated imide into β,γ-unsaturated imide. The Birch reduction using 2-isopropylbenzimidazole realized a concise and stereoselective synthesis of δ-lactone 14, a sex pheromone of Macrocentrus grandii, while the isomerization reaction using 2-methylbenzimidazole was employed in the highly stereoselective synthesis of the γ-lactone intermediate in the synthesis of depsipeptide antibiotics. These bulky proton sources would be powerful tools to achieve a concise synthesis of natural products.
Stereoselective synthesis of (3S,5S,6S)-tetrahydro-6-isopropyl-3,5- dimethylpyran-2-one; A C5-epimer of a component of a natural sex pheromone of the wasp Macrocentrus grandii, the larval parasitoid of the European corn borer Ostrinia nubilalis
Shklyaruck, Denis,Matiushenkov, Evgenii
, p. 1448 - 1454 (2011/11/12)
(3S,5S,6S)-Tetrahydro-6-isopropyl-3,5-dimethylpyran-2-one, a C5-epimer of a component of the natural sex pheromone of the wasp Macrocentrus grandii, the larval parasitoid of the European corn borer Ostrinia nubilalis, was synthesized starting from methyl l-valinate. The transformation includes a Kulinkovich cyclopropanation reaction, a cationic cyclopropyl-allyl rearrangement of cyclopropyl methanesulfonate, a diastereoselective alkylation of Oppolzer's (N-propionyl)-(2R)-bornane-10,2-sultam and a diastereoselective hydrogenation using Wilkinson's catalyst as the key steps.
Asymmetric synthesis of a sex pheromone (3S,5R,6S)-3,5-dimethyl-6-isopropyl-3,4,5,6-tetrahydropyran-2-one
Prabhakar, Peddikotla,Rajaram, Singanaboina,Venkateswarlu, Yenamandra
experimental part, p. 1806 - 1808 (2009/12/26)
An Oppolzer anti-aldol approach for the synthesis of the sex pheromone (3S,5R,6S)-3,5-dimethyl-6-isopropyl-3,4,5,6-tetrahydropyran-2-one is reported.
Stereochemistry of the reaction of Si-phenyl silenes with butadienes: Elaboration of the silacycloadducts to provide a novel route to substituted lactones
Sanganee, Mahesh J.,Steel, Patrick G.,Whelligan, Daniel K.
, p. 2393 - 2402 (2007/10/03)
Silenes generated through a silyl-modified Peterson olefination procedure can be trapped with a range of alkyl butadienes via a [4 + 2] cycloaddition pathway to afford silacycles accompanied by variable amounts of competing ene, [2 + 2] and silene dimer b
Silenes as novel synthetic reagents: synthesis of diols and lactones from simple alkyldienes
Berry, Malcolm B.,Griffiths, Russell J.,Sanganee, Mahesh J.,Steel, Patrick G.,Whelligan, Daniel K.
, p. 9135 - 9138 (2007/10/03)
Aryl substituted silenes can be generated by a modified Peterson olefination reaction and trapped in situ to afford silacycles with high diastereoselectivity. These silacycles can be elaborated by 'Fleming-Tamao' type oxidation to provide access to functionalized diols and lactones.
o-DPPB-directed stereoselective conjugate addition of organocuprates
Breit, Bernhard,Demel, Peter
, p. 2833 - 2846 (2007/10/03)
Substrate-directed diastereoselective conjugate addition of Gilman cuprates to acyclic enoates has been achieved with the aid of the substrate- bound reagent-directing o-DPPB-group (o-DPPB=ortho-diphenylphosphanyl benzoate). Combining o-DPPB-directed hydroformylation with the o-DPPB- directed cuprate addition provides access to building blocks with up to four stereogenic centers, which may be of relevance for polyketide synthesis. Limit and scope of the o-DPPB-directed cuprate addition of Gilman cuprates with respect to enoate structure as well as control experiments which probe the role of the o-DPPB group are reported. (C) 2000 Elsevier Science Ltd.
A convergent and stereoselective synthesis of the sex pheromone of Macrocentrus grandii
Lin, Guo-Qiang,Xu, Wei-Chu
, p. 5907 - 5912 (2007/10/03)
The synthesis of (3S,5R,6S)-3,5-dimethyl-6-isopropyl-3,4,5,6-tetrahydropyran-2-one (1), the sex pheromone of the larval parasitoid M. grandii, is described.
Synthesis of (2S,4R,5S)-2,4,6-Trimethyl-5-heptanolide, a Sex Pheromone Component for Macrocentrus grandii
Kiyota, Hiromasa,Mori, Kenji
, p. 1120 - 1122 (2007/10/02)
(2S,4R,5S)-2,4,6-Trimethyl-5-heptanolide (1), a sex pheromone component for Macrocentrus grandii, was synthesized by starting from methyl (R)-citronellate (2) and employing bromolactonization (10 -> 11) as the key reaction.
Synthesis of Sex Pheromone 3,5-cis-Dimethyl-6-trans-isopropyl-3,4,5,6-tetrahydropyran-2-one
Raju, Satya V. N.,Pandey, Bipin
, p. 1439 - 1440 (2007/10/02)
An expeditious stereoselective synthesis of sex pheromone (+/-)3,5-cis-dimethyl-6-trans-isopropyl-3,4,5,6-tetrahydropyran-2-one of larval parasitoid M. grandii, from readily available isobutyraldehyde and furan is described.
