Affiliation:
1. Institut für Organische Chemie Albert-Ludwigs-Universität Freiburg Albertstr. 21 79104 Freiburg im Breisgau Germany
2. DISFARM, Sezione di Chimica Generale e Organica “A. Marchesini” Università degli Studi di Milano Via Venezian 21 20133 Milano Italy
3. Department Chemie Ludwig-Maximilians-Universität München Butenandtstraße 5–13, Haus F 81377 München Germany
Abstract
AbstractWe report herein of a novel, enantioselective and rhodium‐ catalyzed cyclisation of allenyl alcohols towards chiral α‐vinylic, cyclic ethers employing a rhodium/(R,R)‐Me‐ferrocelane catalyst. The corresponding chiral cyclic products were obtained in general high yields and enantioselectivities. The synthetic value of our obtained products was further exemplified by transformations of the allylic ether function. Furthermore, applying our newly developed method in our previously reported route towards the total synthesis of (R,R,R)‐α‐tocopherol, we accomplished a significantly improved 2nd generation synthesis of the chromane building providing a total number of 13 steps and an overall total yield of 27 %.