Sordaria araneosa

Recently, Mander and coworkers [122] reported the total synthesis of sordaricin (4-347), the aglycone of the potent antifungal diterpene sordarin which was first isolated in 1971 from the ascomycete Sordaria araneosa. Two approaches were explored the first method utilized a possible biogenetic Diels-Alder reaction the second was based on a domino retro-Diels-Alder/intramolecular Diels-Alder process. Thus, heating of 4-348 led, with extrusion of cyclopentadiene, to a 1,3-butadiene as intermediate which underwent an intramolecular Diels-Alder reaction to give the desired 4-349 as the main product, together with a small amount of 4-350 (Scheme 4.77). 

Mander and Thomson reported the total synthesis of sordaricin (120), a diterpene isolated from the ascomycete Sordaria araneosa Cain (Scheme 8.19) [51]. Inspired by its biogenesis, they devised a synthetic plan involving a domino retro Diels-Alder/IMDA reaction of a mask cyclopentene 121. Upon liberation of cyclopentene, intermediate 122 underwent an IMDA reaction to give the desired sordaricin analog 123 along with a minor cycloaddnct regioadduct 124. 

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