Organocatalytic regioselective acylation of mono- and disaccaharides with various functionalized acid anhydrides has been developed. Acylation of octyl beta-D-glucopyranoside with acid anhydrides derived from alpha-amino acids, cinnamic acid, and gallic acid took place at C(4)-OH with 67-94% regioselectivity in the presence of catalyst 1. Regioselective acylation of disaccharides with functiona...

this study was performed to design bilayer regioselective floating tablets of atenolol and lovastatin to give immediate release of lovastatin and sustained release of atenolol. bilayer floating tablets comprised two layers, i.e immediate release and controlled release layers. the immediate release layer comprised sodium starch glycollate as a super disintegrant and the sustained release layer c...

Treatment of acetyl- 1,4-benzoquinone with isoprene gave the corresponding regioselective adduct (I). Rearrangement of the adduct (1) in pyridine and methanol gave 2-acetyl-5, 8-dihydro-6-methyl- 1,4-dihydroxynaphthalene (2). Silver oxide oxidation of the rearranged product (2) gave 2-acetyl-5,8-dihydro- 6-methyl- 1,4naphthalenedione (3). Regioselective addition of trans-piperylene to this...

Strategies for regioselective C-H trifluoromethylation of heteroaromatic compounds are summarized herein. This review article consists four sections: (1) Introduction; (2) five-membered compounds; (3) six-membered and (4) Conclusion. Each section is categorized by the reaction sites. Regioselective summarized.

Treatment of 2-methylphenols with chloro(diphenyl)-λ-iodane led to their regioselective dearomatizing 2-phenylation into cyclohexa-2,4-dienone derivatives via a proposed ligand coupling reaction. In the same vein of investigation, treatment of 2-methylanilines with the λ-iodane 2-iodoxybenzoic acid IBX reagent led to their regioselective dearomatization into previously undescribed ortho-quinol ...

A regioselective Heck reaction of aliphatic olefins and aryl bromides is realized at internal carbons of olefins. Methanol solvent promoted halide ionization from neutral arylpalladium halide complexes via hydrogen bonding, so as to create cationic aryl-Pd species for regioselective olefin insertion.

The total synthesis of (+)-cavicularin is described. The synthesis features an enantio- and regioselective pyrone Diels-Alder reaction of a vinyl sulfone to construct the cyclophane architecture of the natural product. The Diels-Alder substrate was prepared by a regioselective one-pot three-component Suzuki reaction of a non-symmetric dibromoarene.

[reaction: see text] A short synthesis of (+/-)-brazilin is reported. This synthesis uses several interesting and underutilized transformations including a regioselective dirhodium-catalyzed aryl C-H insertion, a regioselective IBX phenol --> o-quinone oxidation, a tautomerization of an o-quinone to a p-quinone methide, and an intramolecular aryl cyclization with a p-quinone methide.

Saponarin, apigenin 6-C- and 7-O-bis-β-D-glucoside, was synthesized in an overall yield of 37% via 11 steps, which included the C-glycosylation of 2,4-O-dibenzylphloroacetophenone, the introduction of a cinnamoyl residue by aldol condensation, the formation of a flavone by regioselective deprotection, and oxidative ring-closure to the final regioselective deprotection and stereoselective O-glyc...

A regioselective synthesis of 6-ω-alkenyluridines 3, precursors of potent antiviral and antitumor cyclonucleosides 5, is described. While ω-alkenyl halides do not alkylate 6-lithiouridine, compounds 3 were prepared in a regioselective manner by sequential treatment of 6-methyluridine 2 with LTMP or LDA (4 equiv) in THF at -30 °C followed by alkylation with ω-alkenyl bromides.