Intramolecular dienophile transfer. Diels-alder adducts of acyl-nitroso compounds as useful reagents for intramolecular cycloadditions.
✍ Scribed by Gary E. Keck
- Publisher
- Elsevier Science
- Year
- 1978
- Tongue
- French
- Weight
- 243 KB
- Volume
- 19
- Category
- Article
- ISSN
- 0040-4039
No coin nor oath required. For personal study only.
✦ Synopsis
In connection with synthetic programs underway in these laboratories, we required certain 3-hydroxy-4,6-heptadiene-hydroxamic acids (1) for use as precursors to the corresponding acylnitroso compounds. Thus Kirby has reported that periodate oxidation of hydroxamic acids generates highly reactive acyl-nitroso compounds which can be trapped by dienes to afford products of I4 + 21 cycloaddition.' We envisioned, based upon the yields obtained for a series of biomolecular processes (e.g. 65-702 for reaction of nitroso-carbonyl benzene with 1.2 eq of cyclohexadiene at 23' in dimethylformamide2) that oxidation of hydroxamic acids such as 1 would furnish intramolecular Diels-Alder adducts in exceptionally high yield. Reductive cleavage of the nitrogen.