Pancratistatin (PST) is a natural compound initially extracted from spider lily,[1] a Hawaiian native plant of the family Amaryllidaceae[2] (AMD).

It has been shown that the enrichment of atmospheric CO2 can enhance the production of antiviral secondary metabolites, including pancratistatin, in these plants.

However, the compound has to be commercially extracted from field- and greenhouse-grown bulbs or from tissue cultures cultivated, for example, in Arizona, which generate lower levels of pancratistatin (a maximum of 22 mg/kg) even in the peak month of October.

Field-grown bulbs, which show monthly changes in pancratistatin content, generate somewhat smaller amounts (2–5 mg/kg) compared to those grown in greenhouses cultivated over the same period.

According to Danishefsky and Joung, there were several weak steps in this synthesis that gave rise to a disappointing low synthetic yield.

Amongst the most challenging issues, the Moffatt transposition and the orthoamide problem, which required a blocking maneuver to regiospecifically distinguish the C, hydroxyl group for rearrangement were considered to be the severe cases.

[13] The key step of this synthesis was the Nickel catalyzed dearomatization of benzene which directly installed the amine and catachol ring in 98:2 er.

A very recent approach to a stereocontrolled pancratistatin synthesis was accomplished by Sanghee Kim from the National University of Seoul, in which Claisen rearrangement of dihydropyranethlyene and a cyclic sulfate elimination reaction were employed 21.

Saponification of the methyl ester 11 with LiOH was followed by a Curtius rearrangement of the resulting acid 12 with diphenylphosphoryl azide in refluxing toluene to afford an isocyanate intermediate, treatment of which with NaOMe/MeOH forms the corresponding carbamate 13 in 82% yield.

Peracetylation of 19 (77% yield) accompanied by Banwell’s modified Bischler-Napieralski reaction forms the compound 20 with a small amount of isomer 21 ( 7:1 regioselectivity).