A Tether Controlled exo-Selective Trans-Annular Diels-Alder (TADA) Reaction

Felzmann, Wolfgang; Arion, Vladimir B.; Mieusset, Jean-Luc; Mulzer, Johann.   

Organic Letters  (2006),  8(17),  3849-3851.

A fully substrate controlled stereoselective route to construct cis-hexahydronaphthalene 4 is described starting from nonracemic butenolide 6. The key step is an exo-selective transannular Diels−Alder reaction (TADA) of tetraene 5, whose intrinsic constraint allows selective formation of one stereodefined product. Compound 4 is a key intermediate in the synthesis of the novel antibiotic branimycin (1).