✦ LIBER ✦
First [4+2] Cycloadditions Involving the Olefinic Bond of an ‘Aldoketeniminium Salt’ (=N-Alk-1-enylideneaminium Salt)
✍ Scribed by Florence Mahuteau-Betzer; Ping-Yu Ding; Léon Ghosez
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- German
- Weight
- 227 KB
- Volume
- 88
- Category
- Article
- ISSN
- 0018-019X
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
‘Keteniminium triflates’ (=N‐alk‐1‐enylideneaminium trifluoromethanesulfonates; [MeN(Ts)CHC NR^1^(R^2^)]^+^TfO^−^) generated in situ from N^α^‐tosylsarcosinamides MeN(Ts)CH~2~CONR^1^(R^2^) unexpectedly react with cyclopenta‐1,3‐diene and cyclohexa‐1,3‐diene to give Diels–Alder reactions across the CC bond of the cumulene. The use of N^α^‐tosylsarcosinamides derived from chiral pyrrolidines allows the direct preparation of trinorbornenone derivative 6 in high enantiomer purity.