Vitamin E-quinone-nickel(0)-cycloocta-1,5,-dine

✍ Scribed by Dr. G. N. Schrauzer; Dipl.-Chem. H. Thyret

• Publisher: John Wiley and Sons
• Year: 1962
• Tongue: English
• Weight: 237 KB
• Volume: 1
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.196204043

✦ Synopsis

Cyclopentadienone [ I ] dimerises in the nascent state at 5 "C. The reaction is not reversible and gives the product (I) (endo- configuration [2]). In the presence of excess ethylene glycol in benzene, the dimer (I) yields the monoketal (II), m.p. 94-95 "C, crude yield 94 %. The position of the keto group follows from the ultraviolet and infrared spectra. If (11) is subjected to pyrolysis at 400°C in vucuo, it is converted almost quantitatively into the ethylene ketal (IV) of the unknown 8,9-dihydroindenone. Carbon monoxide is evolved. The product (Iv) exhibits the typical ultraviolet spectrum of 8,9-dihydroindene [3]; on catalytic hydrogenation it takes up 3 moles of hydrogen.