I. Lyapkalo, M. Webel, H. Reissig
Mar 1, 2002
Citations
0
Influential Citations
18
Citations
Journal
European Journal of Organic Chemistry
Abstract
The fluoride-catalysed reaction between silyl enol ethers 1 and nonafluorobutanesulfonyl fluoride (NfF) has been optimized, resulting in an expedient synthesis of the corresponding alkenyl nonaflates 3. Tetra-n-butylammonium fluoride, dried either with molecular sieves or with potassium fluoride, and potassium fluoride in the presence of dibenzo-18-crown-6 were the best and most practical catalysts for this process. The reaction allows the synthesis of a wide variety of cyclic and acyclic alkenyl nonaflates 3 in good to excellent yields. For E/Z isomeric alkenes the configuration of the double bond is essentially retained. Remarkably, enolates derived from methyl ketones also provide C-sulfonylation products 4 as a side product; the desired alkenyl nonaflates 3l and 3m could, however, be prepared in good yields by further optimization. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)