Isao Iwataki

Flash vacuum pyrolysis of 2-alkoxyiminated alkyl α-pyrone and 1,3-diazine derivatives

Abstract Flash vacuum pyrolysis of 6-ethyl-3-(1-ethoxyiminopropyl)-4-hydroxy-2H-pyrane-2-one (1) and 1,3-dimethyl-5-(1-ethoxyiminopropyl)-6-hydroxy-1,2,3,4-tetrahydropyrimidine-2,4-dione (2) were studied between 300 and 400°C, with nitrogen as the carrier gas. Compound 1 afforded a 1-azirine and the isomeric oxazole, while an oxime and an amide were the reaction products of 2. The difference in reactivity is discussed in terms of the tautomeric structures present in both compounds.

Recent Advances in Peroxidizing Herbicides (Patent Overview)

It is well known that diphenyl ethers, 1-phenylpyrazoles, and O-phenylcarbamates are herbicides which inhibit protoporphyrinogen oxidase (Protox) (Duke et al. 1991; Nandihalli et al. 1992, Nandihali and Duke 1994 see Chapter 6). In addition to these compounds, cyclic imide type Protox inhibitors have been thoroughly investigated recently.

Azirines from the flash vacuum pyrolysis of oximes

Abstract Flash vacuum pyrolysis of a 2-alkoxyiminated-alkyl and a 2-alkoxyiminated-aryl cyclohexane-1, 3-dione derivative was carried out. In these reactions isoxazoles as well as isomeric oxazoles and azirines were found. Two reaction mechanisms involving an iminyl radical and an α elimination are discussed.

SYNTHESES AND HERBICIDAL ACTIVITIES OF SULFUR CONTAINING CYCLOHEXANEDIONE DERIVATIVES

To find out a compound which possesses potent herbicidal activities against not only annual grass weeds but also perennial ones for the control of them in soybean fields, exhaustive synthetic studies have been made. In the last analysis of the structure-activity correlation the synthetic approach was directed toward introduction of sulfur containing substituents at the 5-position on the cyclohexane molecule. In order to introduce such substituents into the molecule at an appropriate stage several synthetic methods were attempted using aldehydes or γ-bromocrotonic acids as starting materials. In the preparation of 2-acylcyclohexanediones, direct acylation and the Fries rearrangement of the corresponding O-acylated substances were attempted contrasting with known methods. Herbicidal activities of the newly prepared compounds were also discussed.