103844-12-8Relevant articles and documents
SYNTHESIS OF LIGNANS RELATED TO THE PODOPHYLLOTOXIN SERIES
Pelter, Andrew,Ward, Robert S.,Pritchard, Martyn C.,Kay, I. Trevor
, p. 1603 - 1614 (2007/10/02)
The dibenzyl-γ-butyrolactone derivative (6), readily prepared by tandem conjugate addition to but-2-en-4-olide, undergoes cyclisation with trifluoroacetic acid to afford retrochinensin (10).After desulphurisation of (6) with Raney nickel, cyclisation yields the aryltetralin lactone (9).Treatment of (6) with concentrated perchloric acid gives a quantitative yield of the rearranged compound (11), which after appropriate modification can be cyclised to afford either the retro-dihydroarylnaphthalene lactone (13), or the 4-substituted aryltetralin lactone (15).Extension of this approach to a second dibenzylbutyrolactone derivative (21) leads to the retro-dihydroarylnaphthalene lactone (25), but gives only a low yield of the required podophyllotoxin derivative (27).