Derivatives of a novel scaffold, C-phenyl 1-thio-D-glucitol, were prepared and evaluated for sodium-dependent glucose cotransporter (SGLT) 2 and SGLT1 inhibition activities. Optimization of substituents on the aromatic rings afforded five compounds with potent and selective SGLT2 inhibition activities. The compounds were evaluated for in vitro human metabolic stability, human serum protein binding (SPB), and Caco-2 permeability. Of them, (1S)-1,5-anhydro-1-[5-(4-ethoxybenzyl)-2-methoxy-4-methylphenyl]-1-thio-D-glucitol (3p) exhibited potent SGLT2 inhibition activity (IC(50) = 2.26 nM), with 1650-fold selectivity over SGLT1. Compound 3p showed good metabolic stability toward cryo-preserved human hepatic clearance, lower SPB, and moderate Caco-2 permeability. Since 3p should have acceptable human pharmacokinetics (PK) properties, it could be a clinical candidate for treating type 2 diabetes. We observed that compound 3p exhibits a blood glucose lowering effect, excellent urinary glucose excretion properties, and promising PK profiles in animals. Phase II clinical trials of 3p (TS-071) are currently ongoing.

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We describe the total syntheses of natural pseurotins A and F2, inhibitors of chitin synthase, both of which possess an unusual 1-oxa-7-azaspiro[4.4]non-2-ene-4,6-dione ring system. The total syntheses of these spiro-hetereocyclic natural products feature: 1) a stereoselective preparation of two segments, i.e., a 2,3-dihydroxylated heptenal derivative and a highly functionalized γ-lactone, each from d-glucose, 2) the connection of the two segments via an aldol-type carbon–carbon bond formation, 3) spirocyclic ring formation from the aldol adduct through convenient 3(2H)-furanone formation, 4) the transformation of a spirocyclic γ-lactone into a γ-lactam hemiaminal derivative, and 5) conversion of the benzyl substituent in the γ-lactam ring into a benzoyl group via a cyclic enamide followed by m-CPBA oxidation in the final stage of the total synthesis. In the initial stage, the quaternary spiro-carbon center in the target molecules was efficiently constructed by a stereochemically exclusive vinyl Grignard addition to the d-glucose-derived 3-ulose. Furthermore, the preparation of the γ-lactone included a stereo- and regioselective Cu(I)-mediated benzyl Grignard addition to aldehyde. We have also completed the total synthesis of a structurally related novel angiogenesis inhibitor, azaspirene, using the analogous reaction sequence.