Katsuhiko Nagahara

Synthesis of a novel dioxane nucleoside having two bases, 2(R)-(5-fluorouracil-1-yl)-5(R)-hydroxymethyl-3(R)-(uracil-1-yl)-1,4-dioxane and its 2(S)-isomer, from uridine

A novel dioxane nucleoside for chemotherapy, 2(R)-(5-fluorouracil-1-yl)-5(R)-hydroxymethyl-3(R)-(uracil-1-yl)-1,4-dioxane and its 2(S)-isomer, were conveniently synthesized from uridine with several steps including periodate oxidation, partial reduction to form hemiacetals, and glycosidation of the second base, 5-fluorouracil, using stannic chloride as the catalyst.

Study of thiazolo[4,5-d]pyrimidines: the synthesis of thiazolo[4,5-d]pyrimidine-2,7-diones and novel ring opening to 2,4-thiazolidinedione

Treatment of 7-oxo-3-phenylthiazolo[4,5-d]-pyrimidine-2(6H)-thione (1) with dimethyl sulfate afforded 6-methyl-3-phenylthiazolo[4,5-d]pyrimidine-2,7-dione (2), 3-phenylthiazolo[4,5-d]pyrimidine-2,7(6H)-dione (3) and/or 5-N-methylcarbamoyl-3-phenyl-2,4-thiazolidinedione (5), depending on reaction conditions. Furthermore, reaction of 3 with dimethyl sulfate caused the ring opening to give corresponding 5. Also, treatment of 5 with phosphorus oxychloride gave 4-chloro-2-oxo-3-phenylthiazolidine-5-N-methylcarboxamide (6)