Asymmetric synthesis of lignans of the dibenzylbutanediol and tetrahydrodibenzocyclooctene series
1993; Issue: 21 Linguagem: Inglês
10.1039/p19930002631
ISSN2050-8255
AutoresAndrew Palter, Robert S. Ward, D. Martin Jones, Peter Maddocks,
Tópico(s)Biological Activity of Diterpenoids and Biflavonoids
ResumoEnolate anions obtained by conjugate addition to (–)-5-(1-menthyloxy)furan-2(5H)-one are quenched with benzyl bromides or iodides to yield homochiral dibenzylbutyrolactones. Desulfurisation followed by lithium aluminium hydride reduction affords homochiral 2,3-dibenzylbutane-1,4-diols, including (–)dimethylsecoisolariciresinol and (–)-dihydroclusin. Desulfurisation followed by reduction with NaBH4/KOH gives the homochiral 2,3-dibenzylbutyrolactones (–)-dimethylmatairesinol, (–)kusunokinin and (–)-yatein, which undergo stereoselective oxidative coupling with DDQ in trifluoroacetic acid to give homochiral tetrahydrodibenzocyclooctene lignans belonging to the isostegane series.
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