Yuki Komatsu

Novel and Efficient Chromium(II)-Mediated Desulfonylation of α-Sulfonyl Ketone

A novel and efficient method for the Cr(II)-mediated desulfonylation of α-sulfonyl ketone by a Cr-ligand-Mn system has been developed during the course of process research on Halaven (eribulin mesylate). This reaction is dramatically accelerated in the presence of an appropriate bipyridyl-type ligand. This system is applicable to reduction of α-sulfur-substituted ketones. In addition, a Cr-Cp2ZrCl2-Mn catalytic system is also applicable to desulfonylation of α-sulfonyl ketone.

Practical syntheses of the adhesion molecule inhibitor ER-49890 and its stereoisomer

Practical synthetic routes to anti-[3-(10H-pyrazino[2,3-b][1,4]-benzothiazin-8-ylmethyl)-3-azabicyclo[3.3.1]non-9-yl]acetic acid (ER-49890, 1) and its syn-isomer are reported. The anti-(3-azabicyclo[3.3.1]non-9-yl)acetic acid side chain (anti-12) was synthesized stereoselectively using Pd/C hydrogenation in the presence of HCl. The syn-isomer (syn-12) was concisely obtained by crystallization as its oxalic acid salt from a 1:1 mixture of anti- and syn-isomers. The 10H-pyrazino[2,3-b][1,4]benzothiazine core (7) was prepared from commercially available 4-chloro-3-nitrobenzyl alcohol (13) in four steps and good yield.

Synthesis of a radiolabelled new oral cephalosporin, E1101

The new broad-spectrum oral antibacterial agent E1101, has been labelled in the C-2 position of the aminothiazole ring using [ 14 C]thiourea. The cephalosporin analog was synthesized in 5 steps and is suitable for metabolism and disposition studies.