Thermodynamic stabilities and conformational analyses of 4,6-O-acetalized 1,5-anhydro-5-thio-DL-threo-2-enitols.
4,6-O-Methylidene and 4,6-O-neopentylidene derivatives of 1,5-anhydro-2,3-dideoxy-5-thio-DL-thero-hex-2-enitol having the C-inside form were found to be thermodynamically more stable than the corresponding O-inside conformers. Thermodynamic stabilities, as well as the conformation of sulfoxide and sulfone derivatives of the 4,6-O-neopentylidene compound were examined by experiment and ab initio MO and DFT calculations. These thermodynamic stabilities, and the most stable conformations determined by NMR data, were corroborated by calculations.
Watanabe
Yuhya
Y
Graduate School of Integrated Science, Yokohama City University, 22-2, Seto, Kanazawa-ku, Yokohama 236-0027, Japan.
Sakakibara
Tohru
T