Reaction of α-chloro-α-phenylselenoesters with silyl enol ethers. Synthesis of α-phenylseleno-γ-keto esters and γ-butyrolactones

Total Synthesis and Biological Evaluation of (−)-Pectinatone Employing a Methyl-Branched Wax Ester as Key Building Block

Unnatural (-)-pectinatone ((-)-3) was prepared in five steps starting from the highly methyl-branched wax ester 4, employing bromination of the ester enolate and subsequent base-induced elimination to the enoate 6 as the key step. Both (-)-3 and the amides 8b and 8c, which were isolated as by-products in the reaction sequence, displayed antimicrobial activity and cytotoxicity.

Scandium-Catalyzed Carbon-Carbon Bond Formations Using .ALPHA.-Organosulfanyl and Organoselanyl-.ALPHA.-fluoroacetic Acid Derivatives

The scandium-catalyzed reactions of alpha-organosulfanyl and organoselanyl-alpha-fluoroacetates 1-2, acetamides 3-4 and acetonitrile 5 with soft nucleophiles proceeded to give the products 6a-b, 7a-c, 8a-c, 9a-e in good to high yields. We also successfully performed the scandium-catalyzed intramolecular cyclization reactions and obtained the unique 5-methylene-2-oxotetrahydropyrans 16-17.