Novel Regio- and Stereoselective Cascade 6-endo-trig Cyclisations from Polyene Acyl Radical Intermediates Leading to Steroid-Like Pentacycles and Heptacycles
摘要:
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 C-13-NMR spectra.
Handa, Sandeep; Pattenden, Gerald, Journal of the Chemical Society. Perkin transactions I, 1999, # 8, p. 843 - 845
作者:Handa, Sandeep、Pattenden, Gerald
DOI:——
日期:——
Novel Regio- and Stereoselective Cascade 6-endo-trig Cyclisations from Polyene Acyl Radical Intermediates Leading to Steroid-Like Pentacycles and Heptacycles
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 C-13-NMR spectra.