115408-60-1Relevant academic research and scientific papers
Syn -Selective crotylation of aldehydes using bismuth-crotyl bromide-(1-butyl-3-methylimidazolium bromide) combination: Some synthetic applications
Goswami, Dibakar,Koli, Mrunesh R.,Chatterjee, Sucheta,Chattopadhyay, Subrata,Sharma, Anubha
, p. 3756 - 3774 (2017/07/07)
The Bi-[bmim][Br] combination has been found to offer high syn-selectivity in the crotylation of aldehydes with crotyl bromide using practically stoichiometric amounts of the reagents. The room temperature ionic liquid (RTIL), [bmim][Br], activated Bi metal in the presence of oxygen to produce crotylbismuthdibromide, which reacted with the aldehydes at room temperature. The major anti-syn diastereomeric product obtained from the crotylation of (R)-cyclohexylideneglyceraldehyde was utilized for the synthesis of dictyostatin and cryptophycin segments, and (+)-cis-aerangis lactone, using standard synthetic protocols.
A convenient asymmetric synthesis of the octalactin lactone
Sharma, Anubha,Gamre, Sunita,Roy, Siddharth,Goswami, Dibakar,Chattopadhyay, Angshuman,Chattopadhyay, Subrata
, p. 3902 - 3905 (2008/09/21)
A facile asymmetric synthesis of the octalactin lactone was developed staring from (R)-cyclohexylideneglyceraldehyde (1). The key step of the synthesis is an In-mediated diastereoselective crotylation of 1 in water, which furnished the building blocks with the required stereochemistry under operationally simple conditions. Their conversion to the appropriate intermediates, invertive esterification and a ring closing metathesis reaction furnished the target compound.
Crotylation versus propargylation: Two routes for the synthesis of the C13-C18 fragment of the antibiotic branimycin
Felzmann, Wolfgang,Castagnolo, Daniele,Rosenbeiger, Daniela,Mulzer, Johann
, p. 2182 - 2186 (2007/10/03)
The C13-C18 fragment 3 of the novel antibiotic branimycin was prepared along two highly stereocontrolled routes. The first one uses a standard Roush crotylation protocol, whereas the second one proceeds via an allenyl silane propargylation with unexpected stereochemical consequences, which are discussed in detail.
Convenient synthesis of (3R, 4S)-4-methyl-3-hexanol and (S)-4-methyl-3-hexanone, the pheromones of ants
Dhotare,Hassarajani,Chattopadhyay
, p. 1051 - 1054 (2007/10/03)
Synthesis of enantiopure pheromones I and II, both of them bearing chiral methyl branching and an α-oxygenated carbon centre, has been accomplished using compound 2 prepared from D-mannitol as the chiral precursor.
Highly Felkin-Anh Selective Hiyama Additions of Chiral Allylic Bromides to Aldehydes. Application to the First Synthesis of Nephromopsinic Acid and Its Enantiomer
Mulzer, Johann,Kattner, Lars,Strecker, Achim R.,Schr?der, Christian,Buschmann, Jürgen,Lehmann, Christian,Luger, Peter
, p. 4218 - 4229 (2007/10/02)
The chromium(II)-mediated addition ("Hiyama reaction") of the chiral allylic bromides 13, 15, 19, 22, 24, and 27 to achiral and chiral aldehydes proceeds with high Felkin-Anh selectivity with respect to the stereocenter at Cγ in the bromide (Table II). By
Studies of an Intramolecular Diels-Alder Approach to the Nargenicins: Involvement of Boatlike Transition States in the Cyclizations of Substituted 1,7,9-Decatrien-3-ones
Coe, Jotham W.,Roush, William R.
, p. 915 - 930 (2007/10/02)
The intramolecular Diels-Alder reactions of a series of substituted decatrienones were examined in connection with a planned synthesis of the decalin framework of the nargenicin antibiotic family.The cyclization of triene 7 provided cis-fused cycloadduct 9 with very high diastereoselectivity through transition state 7Bboat with a boatlike conformation of the connecting chain.The Diels-Alder reactions of trienes 19-23 generated mixtures of cycloadducts, but again a high preference for cyclization through boatlike transition states was observed.The involvement of boatlike transition states in decatrienone intramolecular Diels-Alder reactions appears to be general.A detailed analysis is presented that shows that, assuming the transition state is early as suggested by numerous other investigations, the boat decatrienone transition state is actually free of destabilizing eclipsing or other unfavorable nonbonded steric interactions.The boat transition state in the decatrienone cis-fused manifold is favored over the chairlike arrangement in part as a consequence of a stabilizing eclipsing sp3-sp2 interaction between the diene and the allylic C-H bond, a relationship that is absent from the chair transition state.
Felkin-Anh-Selective Hiyama Addition to O-Protected Lactaldehydes: A General Solution to the Blastmycinone Stereoproblem.
Mulzer, Johann,Schulze, Thomas,Strecker, Achim,Denzer, Wolfgang
, p. 4098 - 4103 (2011/08/10)
The Hiyama addition of 6a-c to the O-protected lactaldehydes 5a,b, proceeds with high Felkin-Anh selectivity. 7c, readily available in 20-g quantities, is the key intermediate in diastereocontrolled syntheses of all blastmycinolactol diastereomers (1-4a) in enantiomerically pure form.
Stereoselectivity of Electrophile-Promoted Cyclizations of γ-Hydroxyalkenes. An Investigation of Carbohydrate-Derived and Model Substrates
Reitz, Allen B.,Nortey, Samuel O.,Maryanoff, Bruce E.,Liotta, Dennis,Robert, Monahan
, p. 4191 - 4202 (2007/10/02)
We have investigated cyclization reactions of γ-hydroxyalkenes bearing an alkoxy or alkyl substituent on the allylic carbon.A variety of electrophiles N-bromosuccinimide, N-iodosuccinimide, iodine, mercury(II) acetate, mercury(II) trifluoroacetate, mercu
