| abstract |
A new process for converting a terminal formyl group bound to a conjugated double bond of an optionally substituted conjugated polyenaldehyde into a group -CH = CH-CO-CR¹R²OH, in which R¹ is an alkyl group and R² is an alkyl or alkenyl group or R¹ and R² together 1,4- Tetramethylene or 1,5-pentamethylene is to react the polyenaldehyde under basic conditions with 4-R¹, 4-R²-5-methylene-1,3-dioxolan-2-one. Certain carotenoid end products of this process, namely of the formulas R '' - CH = CH-CO-C (CH₃) ₂OH (II ''') and R''' - CH = CH-CO-CR 1 ' R 2' - OH (II ''''), in which R '', R ''', R 1' and R 2 'have the meanings given in the description, are new compounds and are also an object of the present invention. The end products, which largely belong to the field of carotenoids, are used accordingly, for example as dyes or pigments for food, egg yolk, integument and / or subcutaneous fat from poultry and meat and / or integument from fish and crustaceans. |