title: Rearrangement of a cyclohexyl radical to a cyclopentylmethyl radical on the avermectin skeleton.
abstract: The rearrangement of a substituted cyclohexyl radical to a cyclopentylmethyl radical on the skeleton of avermectin B1 was observed experimentally and explored computationally. The Stork-Nishiyama methodology was applied to the macrocycle of interest followed by a Tamao oxidation. The expected 5-6 fused ring product was observed in minor amounts. The major product was a 5-5 fused ring resulting from apparent conversion of the initially formed cyclohexyl radical to a cyclopentylmethyl radical. Preliminary computational results indicate that substituents in the macrocycle induce the rearrangement.
authors.affiliation: Syngenta Crop Protection AG, Basel, Switzerland. fiona.murphy_kessabi@syngenta.com
authors.forename: Fiona Murphy
authors.initials: FM
authors.lastname: Kessabi
authors.forename: Tammo
authors.initials: T
authors.lastname: Winkler
authors.forename: Jennifer A R
authors.initials: JA
authors.lastname: Luft
authors.forename: K N
authors.initials: KN
authors.lastname: Houk
mesh_terms: D003510:Cyclohexanes / Q000737:chemistry*; D003517:Cyclopentanes / Q000737:chemistry*; D007559:Ivermectin / Q000031:analogs & derivatives* / Q000737:chemistry; D010084:Oxidation-Reduction
chemical_list: D003510:Cyclohexanes; D003517:Cyclopentanes; D007559:Ivermectin; C019264:avermectin