Unconventional application of the Mitsunobu reaction: Selective flavonolignan dehydration yielding hydnocarpins

作者:Huang, Guozheng; Schramm, Simon; Heilmann, Joerg; Biedermann, David; Kren, Vladimir; Decker, Michael*
来源:Beilstein Journal of Organic Chemistry, 2016, 12: 662-669.
DOI:10.3762/bjoc.12.66

摘要

Various Mitsunobu conditions were investigated for a series of flavonolignans (silybin A, silybin B, isosilybin A, and silychristin A) to achieve either selective esterification in position C-23 or dehydration in a one-pot reaction yielding the biologically important enantiomers of hydnocarpin D, hydnocarpin and isohydnocarpin, respectively. This represents the only one-pot semi-synthetic method to access these flavonolignans in high yields.