Acetaldehyde → Ethyl 3-(1-propenyl)benzoate
反応式
[Br-].[CH3:2][O:3][C:4]([C:6]1[CH:7]=[C:8]([CH:29]=[CH:30][CH:31]=1)[CH2:9][P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)=[O:5].[O-][CH2:33][CH3:34].[Na+].[CH:36](=O)C>>[CH:9]([C:8]1[CH:7]=[C:6]([CH:31]=[CH:30][CH:29]=1)[C:4]([O:3][CH2:2][CH3:36])=[O:5])=[CH:33][CH3:34]参加物
実験手順
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.
出典と根拠
- ORDレコード
- ord-0788509c82434a748da8ac7bd9f2071b
- 出典データセット
- uspto-grants-1980_09
- 特許番号
- US04225609
反応ノート
読み込み中…