Total syntheses and stereochemical reassignments of mollenines A and B.

Total syntheses of prenylated pyrrolidinoindoline alkaloids, (-)-mollenines A [(-)-1'] and B (2'), were accomplished via three- and four-step sequences including a bioinspired indole prenylation reaction followed by dioxomorpholine ring formation. Then, the stereochemistry of mollenines A and B was reassigned to 3S,6S,14S,16S by analysis of spectroscopic data and chemical syntheses with different approaches along with the comparison of calculated and experimental ECD spectra. In addition, a thermodynamically controlled epimerization reaction on the dioxomorpholine ring was observed in our synthesis.