Takeshi Sugai

Biochemical preparations of both the enantiomers of methyl 3-hydroxypentanoate and their conversion to the enantiomers of 4-hexanolide, the pheromone of trogoderma glabrum

Abstract Both the enantiomers of methyl 3-hydroxypentanoate were prepared by microbial asymmetric reduction of 3-oxopentanoic esters. Conversion of methyl 3-hydroxypentanoate to 4-hexanolide, the pheromone of Trogoderma glabrum, was achieved.

Synthesis of the racemic and optically active forms of gizzerosine, the inducer of gizzard erosion in chicks

Abstract The racemate and both the ( R )- and ( S )-forms of gizzerosine [2-amino-9-(4-imidazolyl)-7-azanonanoic acid] were synthesised, and the ( S )-isomer was identified as the toxic substance in fish meal causing severe gizzard erosion (black vomit) in chicks.

Synthesis of both the enantiomers of 4-dodecanolide, a defensive secretion of rove beetles

The enantiomers of 4-dodecanolide, a defensive secretion of rove beetles, were synthesized from (S)- and (R)-2-aminodecanoic acid obtained by the enzymic resolution of the corresponding chloroacetyl derivative.

THE ABSOLUTE STRUCTURE AND ACTIVITY RELATIONSHIPS OF MAJOR SECONDARY ALCOHOLS OF PYRETHROID INSECTICIDES

ABSTRACT Optically active forms of various χ-ethynyl pyrethroid alcohol moieties were newly prepared for determination of their absolute configurations, and the toxicity ratios of the respective (S)-alcohol ester to the (R)-ester to housefly were assessed. As for the acyclic χ-ethynyl alcohol esters, the toxicity ratios were generally high and consistent over available examples. Whereas, the ratios were essentially dependent on both the species and position of a substituent on the benzene ring regarding the χ-ethynylbenzyl analogs. The essential stereochemical requirements for the active ethynyl alcohols were discussed in comparison with other major secondary alcohols as represented by (S)-allethrolone and (S)-χ-cyano-3-phenoxybenzyl alcohol.

Synthesis of (S)-2-hydroxy-β-ionone, employing (S)-3-hydroxy-2,2-dimethylcyclohexanone as the chiral starting material

(S)-2-Hydroxy-β-ionone of 96% e.e. was synthesized from (S)-3-hydroxy-2,2-dimethyl cyclohexanone, which was easily obtained by the baker’s yeast reduction of 2,2-dimethylcyclohexane-l,3-dione.