Umwandlung des Tricyclo[5,4,0,03,9]undecadiengerüstes in das neue Octahydro-2,5-methano-azulengerüst
✍ Scribed by György Fráater
- Book ID
- 102856488
- Publisher
- John Wiley and Sons
- Year
- 1976
- Tongue
- German
- Weight
- 533 KB
- Volume
- 59
- Category
- Article
- ISSN
- 0018-019X
No coin nor oath required. For personal study only.
✦ Synopsis
Transformation of the Tricyclo[5,4,0,0^3,9^]undecadiene System into the new Octahydro‐2,5‐methano‐azulene System.
1,3,6‐Trimethyl‐tricyclo[5.4.0.0^3,9^]undeca‐5, 10‐dien‐2‐one (1) was successively treated with sodium amide in toluene, potassium hydroxide in water, LiAlH~4~ in ether and TsCl in pyridine to give the p‐toluenesulfonate 5 in 66% overall yield. The solvolysis of 5 resulted in the remarkably clean formation of 6, 8a‐dimethyl‐9‐methyl‐iden‐2,5‐methano‐1,2,3,3a,4,5,8,8a‐octahydroazulene (6). The carboxylic acid 3 upon treatment with thionylchlorid in benzene at 70° underwent a spontaneous intramolecular Friedel‐Crafts acylation to give 9 and 10 which have the same carbonskeleton as 6. The endo‐chloro configuration of 10 was demonstrated by reduction of 10 to 4; this reaction proceeds presumably through a reductive fragmentation, the stereoelectronic requirements of which are given in the endo‐isomer of 10 only.