ABSTRACT
An asymmetric synthesis of HCV NS5B nucleoside polymerase inhibitor (1) is described. This novel route features several remarkably diastereoselective and high-yielding transformations, including construction of the all-carbon quaternary stereogenic center at C-2 via a thermodynamic aldol reaction. A subsequent glycosylation reaction with activated uracil via C-1 phosphate and installation of the cyclic phosphate group using an achiral phosphorus(III) reagent followed by oxidation provides 1.
Subject(s)
Antiviral Agents/pharmacology , Viral Nonstructural Proteins/antagonists & inhibitors , Antiviral Agents/chemical synthesis , Antiviral Agents/chemistry , Hepacivirus/drug effects , Hepatitis C, Chronic/drug therapy , Humans , Molecular Structure , Stereoisomerism , Viral Nonstructural Proteins/metabolismABSTRACT
A practical, enantioselective synthesis of cis-2,5-disubstituted pyrrolidine is described. Application of an enzymatic DKR reduction of a keto ester, which is easily accessed through a novel intramolecular NâC benzoyl migration, yields syn-1,2-amino alcohol in >99% ee and >99:1 dr. Subsequent hydrogenation of cyclic imine affords the cis-pyrrolidine in high diastereoselectivity. By integrating biotechnology into organic synthesis and isolating only three intermediates over 11 steps, the core scaffold of ß3-AR agonists is synthesized in 38% overall yield.
Subject(s)
Adrenergic beta-3 Receptor Agonists/chemical synthesis , Pyrrolidines/chemical synthesis , Adrenergic beta-3 Receptor Agonists/chemistry , Adrenergic beta-3 Receptor Agonists/pharmacology , Amino Alcohols/chemistry , Catalysis , Hydrogenation , Imines/chemistry , Molecular Structure , Oxidation-Reduction , Pyrrolidines/chemistry , Pyrrolidines/pharmacology , StereoisomerismABSTRACT
A novel synthesis of 3-methylindoles from chlorotriflates through a Heck reaction, carbamate/aryl chloride coupling, and isomerization sequence is presented. The three-step sequence is highly efficient and general, enabling the regiocontrolled synthesis of substituted indoles in short order.
