Bromation des enamines du prénal et du crotonaldéhyde. Voie d'accès aux ω-bromo aldéhydes et ω-bromo acétals correspondants.
摘要:
Bromination of enamines of prenal and crotonaldehyde yields the corresponding omega-bromoaldehydes via the simple hydrolysis of iminium salts. The carbonyl function of these aldehydes can be protected as acetals or dioxolane. The overall process can be realized in a one pot procedure. The dioxolane is the starting material of a phosphonate which allows by condensation with beta-ionylidenacetaldehyde a direct access to the retinal with a 27.5% overall yield from the enamine 2
Bromination of enamines of prenal and crotonaldehyde yields the corresponding omega-bromoaldehydes via the simple hydrolysis of iminium salts. The carbonyl function of these aldehydes can be protected as acetals or dioxolane. The overall process can be realized in a one pot procedure. The dioxolane is the starting material of a phosphonate which allows by condensation with beta-ionylidenacetaldehyde a direct access to the retinal with a 27.5% overall yield from the enamine 2