Reaktion #56477
ord-22de681056fc407c8dda1a1f2a14dc87
Reaktionsgleichung
Reagenzien
Lösungsmittel
Reaktionsbedingungen
Aufarbeitung
- 1SonstigeThe preparation
Vorschrift
The preparation of begins with the known methyl 3-(bromomethyl)benzoate. This halide is heated in xylene solution with triphenylphosphine to yield (3-methoxycarbonylbenzyl)triphenylphosphonium bromide. The phosphonium salt is converted to the ylide with sodium ethoxide and the ylide caused to react with acetaldehyde to yield ethyl 3-(1-propenyl)benzoate. (Note that the ethyl ester has been obtained as a result of transesterification with solvent ethanol.) The ester is heated with N-bromosuccinimide in carbon tetrachloride for an extended period to yield ethyl 3-(3-bromo-1-propenyl)benzoate. This compound is treated with the anion derived from methyl methylthiomethyl sulfoxide as described in section (b) above. The resulting dimethylmercaptal S-oxide is hydrolyzed with acid catalysis to ethyl 3-(4-oxo-1-butenyl)benzoate. Hydrogenation of this olefinic aldehyde over a palladium catalyst affords the aldehyde intermediate XXIII.