ol1c00955_si_002.xyz (17.6 kB)
Download file

A Unifying Bioinspired Synthesis of (−)-Asperaculin A and (−)-Penifulvin D

Download (17.6 kB)
posted on 08.04.2021, 16:46 authored by Ian R. George, Miguel López-Tena, Anders P. Sundin, Daniel Strand
The first syntheses of the isomeric dioxafenestrene natural products (−)-asperaculin A and (−)-penifulvin D are reported. Each target is formed selectively by choice of oxidant in a final divergent bioinspired Baeyer–Villiger (BV) reaction. Density functional theory calculations reveal that electrostatic interactions between the oxidant leaving group and the lactone motif accounts for a reversal of selectivity with H2O2/H3O+ compared to peracids. Synthetic features include forging the polycyclic carbon framework with a diastereoselective meta-photocycloaddition biased by an ether substituent at the aryl α-position. The encumbered tertiary alcohol was installed by cyanation of a ketone intermediate followed by nonaqueous hydrolysis of the resulting delicate cyanohydrin.