Preparation and properties of 1, 2-benzodiazepines and 1, 2-diazepines condensed with aromatic heterocyclic rings are reviewed. All these compounds are recently reported new ring systems, which are known as three tautomers, i. e., 1H-, 3H-, and 5H-tautomers.
Fluorene is one of interesting compounds in organic synthesis, owing to its active methylene group. In this paper, the articles dealing with the preparation of fluorenes by the ring closure of five-membered ring from biphenyl, diphenylmethane, and benzophenone derivatives, and by the ring degradation from phenanthrene, fluoranthene, and cyclopenta [def] phenanthrene were reviewed.
The characteristic flavours in plant-, leaf alcohol, cis-3-hexenol, and leaf aldehyde, trans- 2- hexenal, are widely distributed in fresh leaves, vegetables and fruits and are responsible for the odor characteristic of the leaf. Also, both are found in some insect excretions as functioning attractants and repellents. The investigation of leaf alcohol has been carried out by Takei and Ohno et al. since 1938; from 1957, we have been studying leaf alcohol and leaf aldehyde from a number of angles : synthetic chemistry, natural products chemistry, and plant biochemistry. Recently, we focused our attention on the biosynthesis of leaf alcohol and leaf aldehyde and have demonstrated the biosynthetic pathway using Thea sinensis leaves. We know now that leaf alcohol and aldehyde are produced from cis-3-hexenal. This C6-compound, cis-3-hexenal and the C12-compound, 11-formyl-cis-9-undecenoic acid, are biosynthesized from linolenic acid by enzymatic oxygenative splitting through the addition of oxygen to the double bond between C-12 and C-13. This C12-fragment isomerizes to give 11-formyl-trans-10-undecenoic acid, traumatic half aldehyde, which is known as the “Wound Hormone”.
Studies on the reactivities of organophosphorus compounds under anodic oxidation are described. In the anodic oxidation of triphenylphosphine and trialkyl phosphites, the attack of various nucleophiles on the anodically generated cation radical of tervalent organophosphorus compounds to give the corresponding phosphonium salts has been observed. The following anodic reactions take place; anodic alkylamination, anodic arylation, anodic alkoxylation, anodic alkylthiolation, anodic activation, anodic phosphonylation, and anodic phosphorylation. The possibilities of their synthetic applications are also discussed.