Hiroyuki Mitsudera

Guinesine-A, -B and -C: new sulfur containing insecticidal alkaloids from Cassipourea guianensis

Abstract New sulfur containing insecticidal alkaloids, guinesine-A ( 1a ), -B ( 1b ) and -C ( 1c ) have been isolated from the bark of Cassipourea guianensis and their structures determined by spectroscopic studies and X-ray analyses.

The first regiospecific synthesis of helioxanthin by novel palladium-catalyzed benzannulation reaction of α,β-bisbenzylidene-γ-lactone

Abstract We achieved the first regiospecific and biomimetic transformation of α,β-bisbenzylidene-γ-lactone to an arylnaphthalene lignan lactone, helioxanthin, using a novel palladium-catalyzed benzannulation reaction.

Convenient efficient synthesis of TAK-779, a nonpeptide CCR5 antagonist: development of preparation of various ammonium salts using trialkylphosphite and N-halogenosuccinimide

Abstract A convenient and efficient synthesis of TAK-779 (1a), a nonpeptide CCR5 antagonist, has been achieved. The new methylation of tertiary amine (2) using trimethyl phosphite and N-chlorosuccinimide, followed by the addition of HCl led to ammonium chloride (1a) in 89% isolated yield without requiring a chromatographic method. By this preparation, ammonium methanesulfonate (1e) could be obtained in 75% isolated yield.