title: Synthesis and conformations of [2.n]metacyclophan-1-ene epoxides and their conversion to [n.1]metacyclophanes.
abstract: A series of syn- and anti-[2.n]metacyclophan-1-enes have been prepared in good yields by McMurry cyclizations of 1,n-bis(5-tert-butyl-3-formyl-2-methoxyphenyl)alkanes. Significantly, acid catalyzed rearrangements of [2.n]metacyclophan-1-enes afforded [n.1]metacyclophanes in good yield. The ratios of the products are strongly regulated by the number of methylene bridges present. The percentages of the rearrangement products increase with increasing length of the carbon bridges. Characterization and the conformational studies of these products are described. Single crystal X-ray analysis revealed the adoption of syn- and anti-conformations. DFT calculations were carried out to estimate the energy-minimized structures of the synthesized metacyclophanes.
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Engineering, Saga University, Honjo-machi 1, Saga-shi, Saga 840-8502, Japan. yamatot@cc.saga-u.ac.jp.
authors.forename: Thamina
authors.initials: T
authors.lastname: Akther
authors.forename: Md Monarul
authors.initials: MM
authors.lastname: Islam
authors.forename: Shofiur
authors.initials: S
authors.lastname: Rahman
authors.forename: Paris E
authors.initials: PE
authors.lastname: Georghiou
authors.forename: Taisuke
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Junji
authors.initials: J
authors.lastname: Tanaka
authors.forename: Carl
authors.initials: C
authors.lastname: Redshaw
authors.forename: Takehiko
authors.initials: T
authors.lastname: Yamato