Simple preparation of a helical quinone

✍ Scribed by Longbin Liu; Thomas J. Katz

• Book ID: 104226560
• Publisher: Elsevier Science
• Year: 1990
• Tongue: French
• Weight: 311 KB
• Volume: 31
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)94478-2

✦ Synopsis

This procedure uses no light and gives a helicene with an interesting functional group. It is notably simple. An enzymatic hydrolysis is used to obtain the quinone optically active.

Helicenes are scarce in amount, although not in variety,' probably because the key reaction used to prepare them, the photocyclization of stllbenes,ln* is constrained (to prevent photodimerizationsa) to solutions that are very dilute. Because of their scarcity, and because only few have been made with functional groups,4 helicenes have rarely been used as precursors for other materi-alsllBbllcor as reagents.~l~llt

This Is unfortunate, for the helical conjugated structure endows the molecules with exceptional electronic properties, shown by enormous optical actlvity,l~10 and with the ability to induce high asymmetry in chemical transformations.~l~gll Thus procedures that make helicenes without using light, 12 and that make helicenes with useful functionalfty could be of great benefit.

Quinones are studied here because, by reacting with either electron donors.13~14 or dienes,ls many give materials with mobile electrons that are unusally delocalized.