C. Mukai et al., A new entry to oxacycles via base-catalyzed endo mode cyclization of allenyl sulfoxides and sulfones, ORG LETT, 3(21), 2001, pp. 3385-3387
[GRAPHICS]
Treatment of the allenyl sulfoxides and sulfones possessing a proper delta
-hydroxy appendage at the C-1 position with potassium tert-butoxide effecte
d endo mode ring closure at the sp-hybridized carbon center of the allenyl
moiety to provide the five- to eight-membered oxacycles in high yields.