67548-46-3Relevant academic research and scientific papers
B(C6F5)3: A New Class of Strong and Bulky Lewis Acid for Exo-Selective Intermolecular Diels-Alder Reactions of Unreactive Acyclic Dienes with α,β-Enals
Zhou, Jia-Hui,Jiang, Bing,Meng, Fei-Fan,Xu, Yun-He,Loh, Teck-Peng
, p. 4432 - 4435 (2015)
Lewis acid B(C6F5)3 catalyzed the Diels-Alder reactions of multisubstituted open-chain dienes and α,β-enals to afford the desired products with high exo-selectivities are reported. The substituent effect of the dienes and dienophiles on the products stereoselectivity was thoroughly investigated, and it was found that most of the desired exo-Diels-Alder products could be obtained in good yields and with high exo-stereoselectivities.
Computationally guided organometallic chemistry: Preparation of the heptacyclic pyrazine core of ritterazine N
Taber, Douglass F.,Taluskie, Karen V.
, p. 2797 - 2801 (2007/10/03)
Diels-Alder cycloaddition of 10 followed by Wittig homologation and intramolecular diene cyclozirconation of the resulting triene under equilibrating conditions led to the tricyclic 6-6-5 ketone 5 with high diastereocontrol. The derived α-azido ketone 16
Syntheses with Organoboranes. XI. Allylboration of Vinylic Epoxides with Allylic Dialkylboranes
Zaidlewicz, Marek,Krzeminski, Marek P.
, p. 3897 - 3899 (2007/10/03)
equation presented Allylboration of representative vinylic epoxides with allyldiethylborane (1) and (2-cyclohexenyl)dicyclohexylborane (2) affords the corresponding 1,2- and 1,4-addition products. cis-1,2-Addition is favored in the reaction of 1 with 3,4-
Chemoenzymatic deracemization of (±)-2,2-disubstituted oxiranes
Orru, Romano V. A.,Mayer, Sandra F.,Kroutil, Wolfgang,Faber, Kurt
, p. 859 - 874 (2007/10/03)
The preparation of vicinal diols in up to 98% e.e. and 98% yield from the corresponding (±)-2,2-disubstituted epoxides was achieved via an enantioconvergent two-step hydrolysis: Thus, enantioselective enzymatic hydrolysis of the (S)-epoxide proceeded with retention of configuration furnishing the corresponding (S)-diol. In a subsequent step, the remaining (R)-oxirane was hydrolyzed during workup under acid catalysis with complete inversion of configuration yielding the (5)-diol. A detailed study of the latter reaction revealed that the experimental conditions have to be carefully chosen with respect to (i) nature of the acid, (ii) the solvent, and (iii) its water content to avoid racemization.
Reductive Radical Cyclisations of Bromo Acetals and (Bromomethyl)silyl Ethers of Terpenoid Alcohols
Lee, Edward R.,Lakomy, Ivo,Bigler, Peter,Scheffold, Rolf
, p. 146 - 162 (2007/10/02)
The tin hydride promoted and the reductive vitamin B12 catalysed radical cyclisation of mixed 2-bromoacetaldehyde acetals and of (2-bromomethyl)dimethylsilyl ethers of allylic terpenoid alcohols has been investigated: 3-oxadeca-5,9-dien-1-yl radicals undergo 5-'exo' cyclisation to oxolanes (Scheme 4), 3-oxa-2-siladeca-5,9-dien-1-yl radicals sequential 6-'endo' --> 5-'exo' tandem cyclisation to cis-3-oxa-4-silabicyclononanes (Scheme 5), and 3-oxa-2-silatetradeca-5,9,13-trien-1-yl radicals sequential 6-'endo' --> 6-'endo' --> 5-'exo' triple cyclisation to trans-transoid-trans-12-oxa-11-silatricyclo2.6>tridecanes (Scheme 6).
