Pederine asymmetric synthesis

The avmlability of these chiral 3-d>cafbonyl synthons has been put to good use by Evans and Di Mare in an asymmetric synthesis of premonensin (166) and by a Japanese group in the synthesis of (+)-pederin (167). 

Previous synthetic studies that have employed ozonolysis as a means for cleaving oxabicydic substrates include Meinwald s studies toward pederin [138], Just s synthesis of showdowmycin [139], Masamune s synthesis of avenaciolide [140], and Ohno s asymmetric syntheses of (+)-showdowmycin, (-)-cordycepin C, and (-)-6-azapseudouridine [141 a]. 

Similarly, pyran rings are a common early-stage synthetic intermediate in a variety of syntheses. In Kutay and Gademann s synthesis of anguinomycin C, they prepare the heterocyclic portion of the target by combination an electron-rich diene with an unsaturated aldehyde in the presence of Jacobsen s chromium (III) catalyst. Ghosh used the same asymmetric catalyst to promote the reaction of an aldehyde and an electron-rich diene in his synthesis of brevisamide. Rawal synthesized a pyranone for use in his synthesis of pederin by combination of a chiral dienophile with Danishefsky s diene. In his synthesis of phorboxazole B, Burke treated Brassard diene 119 with chiral aldehyde 118 and a europium catalyst to yield pyranone 120. ... 

Matsumoto et al.f starting from the ketone (160), and proceeding by a route which features the 1,5-asymmetric induction in the reduction of (160) to the alcohol (161), elaboration of the latter to (163) via (162), and cyclization to the tetrahydropyran (164). Manipulation of the functionality in (164) then led to the (+)-pedamide (165). This amide was finally coupled to the (+)-acetylpederic acid (166), using a new one-pot method for the synthesis of a-methoxyalkyl amides, leading to pederin (167). 

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