1.
Org Lett
; 23(22): 8878-8882, 2021 11 19.
Artigo
em Inglês
| MEDLINE
| ID: mdl-34714079
RESUMO
A method for the synthesis of 3-methylene-1,4-cycloheptadiene derivatives via an 8π electrocyclization reaction was developed. The triene substrate bearing a phosphate or carbamate group was prepared from γ,δ-unsaturated esters and α,ß-unsaturated aldehydes in four steps. Upon treatment with NaHMDS or KHMDS, the substrate formed a heptatrienyl anion, which underwent electrocyclization and subsequent ß-elimination of the leaving group. The product could be converted into a tropylium salt in two steps.