Naslov
Conformational Chirality of Sulfonylpyrimidine Derivatives

Autori
Višnjevac, Aleksandar ; Luić, Marija ; Žinić, Mladen ; Žinić, Biserka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
22nd European Crystallographic Meeting : Book of Abstracts, Acta Cryst. A60 sxi / Mollnar, Istvan - Budimpešta : IUCr, 2004, 62-62

Skup
22nd European Crystallographic Meeting, ECM22

Mjesto i datum
Budimpešta, Mađarska, 26.08.2004. - 31.08.2004

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Conformational Chirality; Racemic Twinning; Pyrimidine Nucleobases

Sažetak
The title compounds belong to a novel series of pyrimidine nucleobase derivatives possessing a sulfonamide pharmacophore. Some of them exhibit significant anticancer activity in vitro.[1] As the part of the overall structural examination, the crystal structures of 1-tosylthymine (1) and 1-tosyluracil (2) are presented. Both compounds crystallise in orthorhombic system (1 in Pbca and 2 in P212121), whereby the cell volume of 1 is twice as large as the one of 2 (doubling of one axis). The axial conformational chirality was encountered in both compounds, as the consequence of the S1-N1 single bond free rotation hindrance in solid state (atropisomerism). [2] The spontaneous resolution of Ra and Sa enantiomers occured only during the crystallisation of 2, whereas 1 crystallised as a racemate. Formation of chiral crystals of a compound without any stereogenic element is rare and of great interest in the field of absolute asymmetric synthesis in the solid state as well as in connection with the origin of homochirality of life. [3] The SHELXL merohedral twin refinement was applied in the case of the racemically twinned species (2), and the resulting Flack parameter was discussed. The interdependence of the crystal packing and the occurence of the spontaneous resolution was discussed, bearing in mind tiny chemical differences between 1 and 2. [1] Ruđer Bošković Institute (B. Žinić, M. Žinić, I. Krizmanić) EP 0 877 022, 2003. [2] I.D. Cunningham, S.J. Cooles, M.B. Hursthouse, Chem. Comm. (2000) 61-62. [3] I. Azumaya, T. Kato, I. Okamoto, R. Yamasaki, A. Tanatani, K. Yamaguchi, H. Kagechika, H. Takayanagi, Org. Lett. (2003) 5, 3939-3942.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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