Synthesis of Phenostereum A and Related Diol and Attempted Assignment of Relative Configurations of Remote Stereocenters by¹³C NMR

Abstract

Phenostereum A 1 and the related diol 2 were synthesized in enantiopure forms. The diasteromers of different relative configurations showed delicate differences in 13C NMR, revealing mutual influences between the remote stereocenters in such compounds for the first time. Nevertheless, the data for diastereomers of different relative configurations were all fully consistent with those for the natural ones by conventional criteria; assignment of the relative configurations by 13C NMR thus remained impossible. Indications for the relative configurations of the natural products were found by comparison of the 13C NMR deviations from the data for synthetic isomers. The structures for several other natural 2,3‐dihydrobenzofurans were also either confirmed or disproved by synthesis.

In Depth Natural Product Discovery from the Basidiomycetes Stereum Species

“…YMF1.1684 [ 68 ] and Stereum insigne CGMCC5.57, respectively [ 69 ]. Yu et al reported that phenostereum A (125) could be synthesized in an enantiopure form [ 70 ]. Their structures are shown in Figure 7 .…”