title: Thiomaleic anhydride: a convenient building block for the synthesis of alpha-substituted gamma- and delta-lactones through free-radical addition, nucleophilic ring opening, and subsequent thiocarboxylate manipulation.
abstract: Iodoalkyl tert-butyl carbonates and carbamates undergo clean free-radical addition to thiomaleic anhydride to give substituted thiosuccinic anhydrides in high yield on treatment with tris(trimethylsilyl)silane and a radical initiator. After removal of the tert-butyloxycarbonyl group, cyclization then affords lactones or lactams substituted in the alpha-position by a thiocarboxylic acid residue. This group is converted to amides through reaction with electron-deficient sulfonamides or to aldehydes and/or ketones by the reaction of derived thioesters with either thiophenol, an electron-deficient allyl phenyl sulfide, or phenylboronic acid.
authors: Centre de Recherche de Gif, Institut de Chimie des Substances Naturelles, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France. dcrich@icsn.cnrs-gif.fr
authors: David
authors: D
authors: Crich
authors: Md Yeajur
authors: MY
authors: Rahaman
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D000577:Amides / Q000737:chemistry; D000812:Anhydrides / Q000737:chemistry*; D001897:Boronic Acids / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry*; D002625:Chemistry, Organic / Q000379:methods*; D004952:Esters / Q000737:chemistry; D005609:Free Radicals; D007659:Ketones / Q000737:chemistry; D007783:Lactones / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry
chemical_list: D000447:Aldehydes; D000577:Amides; D000812:Anhydrides; D001897:Boronic Acids; D002264:Carboxylic Acids; D004952:Esters; D005609:Free Radicals; D007659:Ketones; D007783:Lactones; D013438:Sulfhydryl Compounds; D013440:Sulfides; C010686:benzeneboronic acid