Step-wise and one-pot synthesis of highly substituted conjugated trienes from 2-oxobenzo[h]chromenes/2H-pyran-2-ones.
Org Biomol Chem
; 19(17): 3901-3910, 2021 05 05.
Article
em En
| MEDLINE
| ID: mdl-33949600
ABSTRACT
A mild and efficient route for the synthesis of conjugated trienes via nitroethane-mediated ring contraction of 2-oxobenzo[h]chromenes/2H-pyran-2-ones followed by decarboxylative rearrangement of the obtained spirobutenolides and butenolides is described. The (E)-isomer of trienes was obtained by step-wise and one-pot approaches from 2-oxobenzo[h]chromenes. Butenolides 4a-l as new substrates have been developed for the construction of trienes. The mixture of the (E)- and (Z)-isomers of spirobutenolides undergoes decarboxylative rearrangement in the presence of sodium ethoxide as a base to yield the (E)-isomer of trienes, while the (E)-isomer of butenolides reacts to give a mixture of (2E,4E)- and (2E,4Z)-isomers of trienes in an almost steady ratio of 45 55 or 1 1.2. The structure and geometry of the obtained butenolides and trienes were confirmed by single-crystal X-ray analysis.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Org Biomol Chem
Assunto da revista:
BIOQUIMICA
/
QUIMICA
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Índia
País de publicação:
ENGLAND
/
ESCOCIA
/
GB
/
GREAT BRITAIN
/
INGLATERRA
/
REINO UNIDO
/
SCOTLAND
/
UK
/
UNITED KINGDOM