✦ LIBER ✦
Unerwartete Bildung von γ-Lactamen aus 6H-1,2,-Oxazinen unter Lewis-Säure-Einwirkung
✍ Scribed by Zimmer, Reinhold ;Reißig, Hans-Ulrich ;Lindner, Hans Jörg
- Publisher
- John Wiley and Sons
- Year
- 1992
- Tongue
- English
- Weight
- 334 KB
- Volume
- 1992
- Category
- Article
- ISSN
- 0947-3440
No coin nor oath required. For personal study only.
✦ Synopsis
Unexpected Formation of γ‐Lactams from 6__H__‐1,2‐Oxazines Promoted by Lewis Acids
The reaction of 6__H__‐1,2‐oxazine 1 with trimethylsilyl cyanide in the presence of titanium tetrachloride provides α,β‐unsaturated γ‐lactam 3. Similarly, Lewis acid‐promoted addition of trimethyl phosphite towards 1 affords a mixture of γ‐lactams 8 and 9. The structure of 9 was established by X‐ray analysis. A plausible mechanism for the formation of these γ‐lactams by Lewis acid‐induced ring contraction is proposed.