Mitsuya Hongu

Discovery of Canagliflozin, a Novel C-Glucoside with Thiophene Ring, as Sodium-Dependent Glucose Cotransporter 2 Inhibitor for the Treatment of Type 2 Diabetes Mellitus

We discovered that C-glucosides 4 bearing a heteroaromatic ring formed metabolically more stable inhibitors for sodium-dependent glucose cotransporter 2 (SGLT2) than the O-glucoside, 2 (T-1095). A novel thiophene derivative 4b-3 (canagliflozin) was a highly potent and selective SGLT2 inhibitor and showed pronounced anti-hyperglycemic effects in high-fat diet fed KK (HF-KK) mice.

Total synthesis of (+)-fumitremorgin B, its epimeric isomers, and demethoxy derivatives

Total synthesis of the title compounds is described. The key intermediate, dehydro-pentacyclic 13, is prepared in a sequence involving Pictet-Spengler reaction and DDQ oxidation. The key step in the synthesis was the dihydroxylation of 13 to afford the cis-diol 54, which was performed by direct oxidation with osmium tetroxide, whereas treatment of 13 with N-bromo-succinimide provided the trans-diol 41. Subsequent selective prenylation of 41 and 54 gave 13-epi-fumitremorgin B (45) and fumitremorgin B (1), respectively. 13-Epi-compound 45 is also converted into fumitremorgin B (1) by oxidation followed by reduction.

Synthetic approach to the total synthesis of fumitremorgins II synthesis of optically active pentacyclic intermediates and their dehydrogenation

Abstract Optically active pentacycles ( 13–18 ) were synthesized from L- and D-tryptophans, two of which ( 13 and 15 ) were alkylated and dehydrogenated to 21 and 22 , respectively.

SOLID-LIQUID PHASE TRANSFER CATALYZED NOVEL GLYCOSYLATION REACTION OF PHENOLS

Abstract A facile and mild glycosylation reaction in solid-liquid two-phase system (powdered K2CO3/CHCl3) containing phase transfer catalyst was found to be efficient for preparation of glucosides of 2′, 6′-dihydroxyacetophenone (1) and other various substituted phenols.