Intramolecular carboxylate capture of an intermediate in aromatic electrophilic substitution. The 8,9,10,11-tetrahydro-7.11-methano-7H-cycloocta[de]naphthalene-9-endo-carboxylic acid system
✍ Scribed by Yaun-Shek Chen; Jeff W. Kampf; Richard G. Lawton
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- French
- Weight
- 204 KB
- Volume
- 38
- Category
- Article
- ISSN
- 0040-4039
No coin nor oath required. For personal study only.
✦ Synopsis
The ~, ~x'-annelation of the enamine of 1,3-dihydro-2-phenalenone with methyl ct-(bromomethyl)acrylate affords an aromatic bieyclie framework, methyl 8,9,10,1 l-telrahydro-7,11-methano-12-keto-TH-cycloocta(de)naphthalene-9-endo-carboxylate having the ester function positioned over the aromatic ring. The 9-exo-methyl-12, 12-dirnethoxy ketal carboxylate anion derivative reacts with excess Br2 in aqueous solution affording the bromo lactone epoxide derived through capture of the intermediate of electorphilic attack on the naphthalene ring, 12, 12dimethoxy-2, 3-endo-epoxy-I la-endo-hydroxy-l-exo, 4-dibromo-7, 1 l-methano-9-methyl-1 la, 1, 2, 3, 4, 8, 9, 10, 11-octahydro-7 H-eyelooeta [de] naphthalene-9-endo-carboxylic acid ~ lactone.