Dinotefuran (MTI-446: (RS)-1-methyl-2-nitro-3-(tetrahydro-3-furylmethyl)guanidine) is a new neonicotinoid commercialized by Mitsui Chemicals. Research led to this novel neonicotinoid by the removal of the chloropyridine or chlorothiazole ring that had been considered as indispensable for neonicotinoides. The research advanced as follows; (1) selection of acetylcholine for the lead compound, (2) recognition of the insecticidal advantages of 3-methoxypropyl compounds, (3) synthesis of (+/-)-tetrahydro-3-furylmethyl compounds by cyclization of the 3-methoxypropyl moiety. It resulted in dinotefuran which has a (+/-)-tetrahydro-3-furylmethyl moiety instead of a halogenated aromatic heterocyclic ring, and belongs to the third-generation neonicotinoids (sub-class: furanicotinyl compounds).

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Dinotefuran ((RS)-1-methyl-2-nitro-3-(tetrahydro-3-furylmethyl)guanidine) is a new neonicotinoid which has a characteristic (Ϯ)-tetrahydro-3-furylmethyl moiety instead of the pyridine-like moiety of other neonicotinoids. A series of dinotefuran derivatives were synthesized and tested against hemiptera. SAR (structure-activity relationships) of the nitroguanidine part of dinotefuran are summarized as follows: (1) the mono-methyl group as a N-substituent gave the best activity for the acyclic nitroimino and nitromethylene compounds, (2) the acyclic compounds showed the same activity as the cyclic compounds against Nephotettix cincticeps and were superior to them against Laodelphax striatellus, (3) N-acylation of this series scarcely changed the level of activity. On the basis of these results, we selected dinotefuran for development.

The (Ϯ)-tetrahydro-3-furylmethyl moiety, which is a characteristic part of the novel neonicotinoid dinotefuran, was found by research in which acetylcholine was selected as the lead compound. SAR (structure-activity relationships) for the tetrahydrofuran part indicated that the non-substituted moiety showed the highest level of activity, 4-and 5-substituted moieties showed intermediate levels, and 2-and 3-substituted moieties lost the activity. Conformational analysis of these compounds indicated that the substituents changed little the hypothetical active conformation of dinotefuran. Computational analysis proved that dinotefuran, a methoxypropyl compound and other neonicotinoids well overlapped, and dinotefuran adopts the active conformation more easily than the methoxypropyl compound.

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An efficient procedure for the conjugate addition method for conjugate addition as well as substitution of y-acetoxy-$-unsaturated ketones with RCu-AlCl, is reactions because of several drawbacks of the ordinary described.organocopper (I) reagents. By using lithium dimethylcuprate (Me,CuLi), it has been reported that y-acetoxy-apunsaturated ketones were reduced to give apand/or &unsaturated ketones.lY2 9, Unfortunately, no successful conjugate addition reaction of y-acetoxy-ap-unsaturated

The chiral synthesis of (+)-saxitoxin and its derivatives is described. Two consecutive carbon–nitrogen bonds at C-5 and C-6 in saxitoxin were effectively installed by the sequential Overman rearrangement of an allylic vicinal diol derived from d-malic acid. The bicyclic guanidine unit was constructed by the intramolecular aminal formation of an acyclic bis-guanidine derivative possessing a ketone carbonyl at C-4. From the bicyclic aminal intermediate, (+)-saxitoxin, (+)-decarbamoyl-β-saxitoxinol [(+)-dc-β-saxitoxinol], and the unnatural skeletal isomer, (−)-iso-dc-saxitoxinol, were synthesized.

Deuterium isotope effects on the metabolic N-demethylation of diuron and monuron were measured in hepatocytes and in liver microsomes of rats. The intermolecular isotope effects were close to unity but the intramolecular effects on the reaction with diuron were 1.99 in hepatocytes (2.33 with monuron) and 2.47 in microsomes. The finding indicated that one electron was removed from nitrogen in the first step of reaction followed by deprotonation. A rapid interchange of two N-methyl groups in the substrate molecules on the enzyme surface was suggested.