Structures and properties of two diastereomeric cyclic sulfites derived from cis-3,4-di-tert-butylthiolane-3,4-diol and thionyl chloride

✍ Scribed by Sanae Tanaka; Yoshiaki Sugihara; Akira Sakamoto; Akihiko Ishii; Juzo Nakayama

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 266 KB
• Volume: 14
• Category: Article
• ISSN: 1042-7163
• DOI: 10.1002/hc.10192

✦ Synopsis

Abstract

cis‐3,4‐Di‐tert‐butylthiolane‐3,4‐diol (1) was treated with an equimolar amount of thionyl chloride in the presence of triethylamine or pyridine in several solvents of different polarity to furnish two diastereomeric sulfites 2a and 2b generally in excellent combined yields. Although 2a was consistently formed as the major diastereomer when pyridine was used as the base, 2a and 2b were formed in approximately equal amounts when triethylamine was used as the base in polar solvents. X‐ray crystallographic analyses revealed that the SO group of 2a is anti to the thiolane ring and that of 2b syn to the thiolane ring. Density functional theory calculations (B3LYP/6‐31G* level) revealed that 2a is less stable than 2b by 1.28 kcal mol^−1^, although 2a was formed generally as the predominant diastereomer. Spectroscopic data of 2a and 2b are discussed with emphasis on comparison with those obtained by calculations. Treatment of 2a and 2b with m‐chloroperbenzoic acid resulted in the oxidation of the divalent sulfur atom of the thiolane ring and not the sulfite sulfur atom. The above oxidations took place exclusively at the syn‐side with respect to the tert‐butyl groups.© 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:587–595, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10192