33651-06-8Relevant academic research and scientific papers
Regio- and Diastereoselective Rhodium-Catalyzed Allylic Substitution with Unstabilized Benzyl Nucleophiles
Pal, Debasis,Wright, Timothy B.,O'Connor, Ryan,Evans, P. Andrew
supporting information, p. 2987 - 2992 (2020/12/09)
We have developed a highly regio- and diastereoselective rhodium-catalyzed allylic substitution of challenging alkyl-substituted secondary allylic carbonates with benzylzinc reagents, which are prepared from widely available benzyl halides. This process utilizes rhodium(III) chloride as a commercially available, high-oxidation state and bench-stable pre-catalyst to provide a rare example of a regio- and diastereoselective allylic substitution in the absence of an exogenous ligand. This reaction tolerates electronically diverse benzylzinc nucleophiles and an array of functionalized and/or challenging aliphatic allylic electrophiles. Finally, the configurational fluxionality of the rhodium-allyl intermediate is exploited to develop a novel diastereoselective process for the construction of vicinal acyclic ternary/ternary stereogenic centers, in addition to a cyclic ternary/quaternary derivative.
3-Alkyl-p-menthan-3-ol derivatives: synthesis and evaluation of their physiological cooling activity
Fuganti, Claudio,Joulain, Daniel,Maggioni, Francesco,Malpezzi, Luciana,Serra, Stefano,Vecchione, Andrea
experimental part, p. 2425 - 2437 (2009/04/06)
Different 3-alkyl-p-methan-3-ol derivatives provide a strong physiological cooling effect with potential application as food and cosmetic additives. In order to investigate the influence of the chemical structure on the cooling sensation, the stereoselective syntheses of 29 different 3-alkyl-p-methan-3-ol derivatives were accomplished. All the compounds obtained are odorless and were evaluated by taste, considering two sensations: a cooling effect and bitterness. The results of this structure-activity relationship study highlight that compounds with a (1R,4S)-configuration are the isomers with the more intense cooling effect and lower bitterness. In addition, the structure of the 3-alkyl chain affected the latter properties. Increasing the chain length over two carbon atoms does not change the cooling power, but enhances the bitterness with the additional feature that the branched isomers are considerably more bitter than the linear ones. Overall, the 3-alkyl-p-menthan-3-ol isomers with the best quality in terms of high cooling power and low bitterness are (1R,4S)-3-(hydroxymethyl)-p-menthan-3-ol diastereoisomers (-)-38 and (-)-42.
Chiral aminoalcohols with a menthane skeleton as catalysts for the enantioselective addition of diethylzinc to benzaldehyde
Panev, Stefan,Linden, Anthony,Dimitrov, Vladimir
, p. 1313 - 1321 (2007/10/03)
Novel chiral aminoalcohols were synthesized by highly diastereoselective addition of Me3SiCN and LiCH2CN to (-)-menthone followed by LiAlH4 reduction. The addition of CH2=CH-MgBr and PhCH=CH-MgBr to menthone and the following epoxidation, provided useful hydroxy epoxides, one of which could be aminolyzed to afford an aminodiol. In one case, the configuration of the newly formed epoxidic stereogenic center was determined by X-ray crystallography. When applied as catalysts in the enantioselective addition of Et2Zn to benzaldehyde, the aminoalcohols induced enantiomeric excesses (e.e.s) of up to 77%.
A Nonresolutive Approach to the Preparation of Configurationally Pure Difunctional Molecules
Chillous, Sandra E.,Hart, David J.,Hutchinson, Douglas K.
, p. 5418 - 5420 (2007/10/02)
Treatment of menthone (5) with organometallic reagents affords axial tertiary alcohols of type 6 with high diastereoselectivity.Propionate 12, derived from trans-11, undergoes an enolate Claisen rearrangement with complete transfer of chirality.The use of
