1,1'-Diacetyloctamethylferrocene: an overlooked and overdue synthon leading to the facile synthesis of an octamethylferrocenophane.

This paper describes the facile preparation of 1,1'-diacetyloctamethylferrocene (2) by acylation of octamethylferrocene (1) with acetyl chloride. Chloroformylation with POCl3 /DMF of 2 affords a variety of products, including 1,1'-bis-(1-chlorovinyl)octamethylferrocene (3b) in high yield. Compound 3b cyclises in aqueous sodium hydroxide/DMF to an octamethyl[1,4]-ferrocenophane bearing a 1-dimethylaminobuta-1,3-diene-handle (4).