Chiroptical properties, structure, and absolute configuration of heterosubstituted 2(5H)-furanones

✍ Scribed by Jacek K. Gawronski; Quing Hua Chen; Zhe Geng; Bin Huang; M. Rosario Martin; Ana I. Mateo; Malgorzata Brzostowska; Urszula Rychlewska; Ben L. Feringa

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 134 KB
• Volume: 9
• Category: Article
• ISSN: 0899-0042
• DOI: 10.1002/(sici)1520-636x(1997)9:5/6<537::aid-chir21>3.0.co;2-o

✦ Synopsis

Chiroptical properties of a series of 3 and/or 4-heterosubstituted 2(5H)furanones were investigated with respect to correlation with absolute configuration. The n -* and -* Cotton effects have been assigned on the basis of comparison with the UV spectra in solvents of varying polarity. It is demonstrated that the n -* transition in 4-amino substituted 2(5H)-furanones appears at shorter wavelength with respect to the -* transition. With the exception of 4-pyrrolidino and 4-benzylamino substituted 2(5H)-furanones, other heterosubstituted 2(5H)-furanones follow the butenolide configurational rule (Gawronski et al. J. Org. Chem. 61:1513-1515, 1996). Absolute configuration of 2(5H)-furanone derivatives can also be assigned according to the sign of the Cotton effect (of unknown origin) at 200-230 nm. The structure of four representative sulfur and nitrogen substituted 2(5H)-furanones has been analyzed by X-ray diffraction.

The results indicate planarity of the furanone ring and extended conjugation in 4-amino substituted 2(5H)-furanones.