Highly Efficient Transfer of Chirality from Macrocyclic Conformation in the Tandem Oxy-Cope/Claisen/Ene Reaction

• Published in: Journal of the American Chemical Society Vol. 126; no. 27; pp. 8569 - 8575
• Main Authors: Sauer, Effiette L. O, Barriault, Louis
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 14-07-2004
• Subjects: Chemistry; Exact sciences and technology; Kinetics and mechanisms; Organic chemistry; Reactivity and mechanisms; Cope rearrangement; Ene reaction; Reaction mechanism; Pericyclic reaction; Claisen rearrangement; Experimental study; Tandem reaction; Diastereoselectivity
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja048301m

We report three highly stereoselective pericyclic reactions occurring in cascade leading to the synthesis of Decalins skeletons possessing two contiguous quaternary centers. The tandem reaction is triggered by an oxy-Cope rearrangement to create in situ a 10-membered ring enol ether macrocyle 6, which immediately rearranges via a Claisen [3,3] shift to the corresponding E-cyclodec-6-en-1-one 7. The latter spontaneously cyclizes via a transannular ene reaction to produce Decalin 5. Analysis of the mechanism with respect to the origin of the high diastereoselectivity of the tandem oxy-Cope/Claisen/ene reaction is presented.