534585-32-5Relevant academic research and scientific papers
Design and synthesis of cyclopropane-based conformationally restricted GABA analogues as selective inhibitors for betaine/GABA transporter 1
Suemasa, Akihiro,Watanabe, Mizuki,Kobayashi, Takaaki,Suzuki, Hiroe,Fukuda, Hayato,Minami, Masabumi,Shuto, Satoshi
, p. 3395 - 3399 (2018)
We previously designed and synthesized a series of cyclopropane-based conformationally restricted analogues of γ-aminobutyric acid (GABA). The study demonstrated that the critical conformation of the analogues that selectively active to betaine/GABA transporter 1 (BGT1) subtype is the trans-syn-form, in which the amino and carboxyl groups are in trans-configuration and the cyclopropane ring and the carboxyl group are in syn-arrangement. In this study, we designed and synthesized cyclopropane-based GABA analogues, which were conformationally restricted in the trans-syn-form by cyclopropylic strain based on the stereochemistry of the carbon adjacent to cyclopropane. Their conformation was confirmed as the syn-form by calculations and NMR studies, and their pharmacological evaluation clarified that compounds 11a and 11d had the BGT1 selectivity, although their inhibitory effects were insufficient.
A systematic study of the hydride reduction of cyclopropyl ketones with structurally simplified substrates. Highly stereoselective reductions of trans-substituted cyclopropyl ketones via the bisected s-cis conformation
Kazuta, Yuji,Abe, Hiroshi,Yamamoto, Tamotsu,Matsuda, Akira,Shuto, Satoshi
, p. 3511 - 3521 (2007/10/03)
The stereoselective hydride reduction of the cis- and trans-substituted cyclopropyl ketones was systematically investigated using a series of structurally simplified substrates, trans-[tertbutyldiphenylsilyloxymethyl]cyclopropyl ketones 1a-e and trans-(benzyloxymethyl)cyclopropyl methyl ketone (2), and the corresponding cis congeners 3a,b,e and 4. The results showed that, not only in the reduction of the cis-substituted cyclopropyl ketones but also in that of the trans-substituted ketones, high stereoselectivity can be realized when the substrate has a bulky substituent on the cyclopropane ring, even though it is attached to the position trans to the acyl moiety. Ab initio calculations based on the density functional theory (DFT) of cyclopropyl ketones showed that (1) the bisected s-cis and s-trans conformers were the only two minimum energy conformers, while the s-cis conformer was more stable than the s-trans and (2) a bulky alkyl group in the acyl moiety and a cis substituent on the cyclopropane ring made the bisected s-cis conformer much more stable. On the basis of these calculations and experimental results, it is likely that the more stable the bisected s-cis conformer of the substrate, the more stereoselective the hydride reduction. Thus, the stereochemistry can be explained by hydride attack on the bisected s-cis conformation of the substrate from the less-hindered face. The predictability of the stereochemical results is predicated on the bisected s-cis transition-state model, which is very important from the viewpoint of synthetic organic chemistry.
