229305-81-1Relevant articles and documents
Novel regio- and stereoselective cascade 6-endo-trig cyclisations from polyene acyl radical intermediates leading to steroid-like pentacycles and heptacycles
Handa, Sandeep,Nair, Prathap S.,Pattenden, Gerald
, p. 2629 - 2643 (2007/10/03)
In a quite remarkable regio- and stereoselective manner, each of the (all-E)-polyene selenoates 5a-c is shown to undergo cascade radical-mediated polycyclisations via consecutive 6-endo-trig reactions, leading to the corresponding all-trans, anti, tri-, penta- and heptacycles, i.e., 20, 23, and 25, in good yields. The configurations of these 'steroid-like' polycycles followed from detailed examination and correlation of chemical shift data in their 13C-NMR spectra.