4324-39-4Relevant academic research and scientific papers
VIBRATIONAL CIRCULAR DICHROISM IN HYDROGEN BOND SYSTEMS Part III. Vibrational circular dichroism of the OH stretching vibrations of 1,2-diols and β-methoxyalcohols
Yamamoto, Kimiko,Nakao, Yoshihiko,Kyogoku, Yoshimasa,Sugeta, Hiromu
, p. 75 - 86 (1991)
Vibrational circular dichroism (VCD) of the OH stretching vibrations in intramolecular hydrogen bond systems, i. e. 1,2-diols and β-methoxyalcohols, has been studied.The VCD feature of the OH stretching mode is discussed in relation to the molecular conformation, with the aid of the results of 1H NMR spectroscopy.The positive VCD observed for the OH stretching vibration of the donor hydroxyl group in intramolecular hydrogen bond systems is attributable to the G- conformation about the O-C-C-O bond.The rotational strengths calculated on the basis of the dynamic polarization model account for the observed VCD feature.
Structural requirements for decarbonylative α,α-diarylation reaction of 2-methoxyalkanoic acids in phosphorus pentoxide-methanesulfonic acid mixture yielding 1,1-diarylalkane homologs
Yonezawa, Noriyuki,Hino, Tetsuo,Tokita, Yoshimi,Matsuda, Kazuhisa,Ikeda, Tomiki
, p. 14287 - 14296 (2007/10/03)
2-Methoxyalkanoic acids were found to undergo consecutive decarbonylative α,α-diarylation in P2O5-MsOH instead of Friedel-Crafts type arylation on the carbonyl carbon. The influence of the substituents of the arenes and the carboxylic acids in this reaction was elucidated based on the reaction yields. The reaction behavior was found to be primarily governed by the electron-withdrawing/releasing property of the α-substituents on the carboxylic acids as well as the positive species-accepting ability of the arenes. The steric hindrance was shown to participate in determining the reaction feasibility as a secondary factor.
Highly Diastereoselective Conjugate Addition of Lithium Dialkylamides to α,β-Unsaturated Esters Having a Chiral Center at the γ-Position
Asao, Naoki,Shimada, Takashi,Sudo, Tomoko,Tsukada, Naofumi,Yazawa, Kazuhiko,Gyoung, Young Soo,Uyehara, Tadao,Yamamoto, Yoshinori
, p. 6274 - 6282 (2007/10/03)
The conjugate addition of lithium amides 2 to tert-butyl 4-(OR)-substituted-2-pentenoates 1 produced a mixture of the syn- and anrt-amino esters (3 and 4) in high yields. Sterically bulky OR groups, such as trityloxy and tert-butyldiphenylsilyloxy, gave t
Stereoselective Radical Additions of γ-Oxy-α,β-unsaturated Ester Derivatives; 1,2-Asymmetric Induction in Acyclic and Cyclisation Systems
Morikawa, Tsutomu,Washio, Yoshiaki,Harada, Susumu,Hanai, Ryo,Kayashita, Takashi,et al.
, p. 271 - 282 (2007/10/02)
Examination was made of 1,2-asymmetric induction in the addition of alkyl radicals to γ-oxy-α,β-unsaturated ester derivatives 1 and 2 prepared from ethyl lactate and (R)-2,3-O-isopropylideneglyceraldehyde 3, respectively.The addition reactions of hexyl, cyclohexyl and 3-phenylpropyl radicals to (Z)-2 derived from aldehyde 3 gave β-addition products with syn-stereoselectivity (syn:anti = 8.6:1 - syn only).The reactions of (E)-2 were non-stereoselective.Based on allylic strain, a transition-state model for the syn-stereoselectivity is proposed. 1,2-Asymmetric induction was carried out in radical cyclisation to synthesize optically active cyclohexane derivatives.
