Photochemical reactions of organophosphorus compounds are reviewed under the following subjects. 1. photochemical formation of organophosphorus compounds. 2. photochemical extrusion of phosphorus group (including photosensitive protective groups and photolysis of phosphorus compounds leading to dephosphorylation). 3. photochemical deoxyganation and desulfurization. 4. photochemical reactions of unsaturated phosphorus compounds.
The study of the chemical conversion of l-abietic acid (1), main component of pine rosin, into optically active natural products with biological activity has been developed at the Institute of Physical and Chemical Research by the late Dr. Akira Tahara. This group's recent works are reviewd for his memory by his staffs. Various types of the acid rearrangements in phenacylidene derivatives of (1) were disclosed and applied to the syntheses of the A-ring substituted diterpenes and a possible intermediate to grayanotoxins. Selective functionalization at 11-, 13-and 14-positions of the aromatic C-ring were established. The 11-substitution reaction was applied to the synthesis of taxodione. Ozonolysis of the phenolic C-ring was proved to be a convenient method for the cleavage of the ring and used for the short-step synthesis of drimane-type sesquiterpenes. Modifications of the isopropyl group, including its methyl migration, made it possible to synthesize d-phyllocladene, d-kaurene, and the skeletons of pimaric acid and steroids. Finally, the synthesis of gibberellin A12 was completed by the combination of the skeletal transformation and the functionality modification of (1).
Retro Mass Spectral Synthesis, which was named by the authors for the retro-process of mass spectral fragmentation and provides an effective method for designing synthetic approach to the total synthesis of several natural products, is explained. Some examples of new general syntheses for ring systems of natural products through “Retro Mass Spectral Synthesis” were reviewed.
Preparation of various heterocyclic compounds by means of main group organometallic compounds are reviewed according to the role of organometallic functions. The consecutive organometallic insertion reactions followed by an appropriate terminal coupling or an affinity-controlled elimination provide a general procedure yielding heterocyclic skeletons. Another application of the organometallic compounds is to modify some unstable substrates into their stable organometallic homologues, which are subjected to the subsequent cycloaddition or condensation.
The synthetic methods for the tetrathiofulvalene (TTF) and the related compounds have been reviewed including the typical experimental procedures. The review also deals with (1) 1, 3-dithiole-2-thiones which are the synthtic key intermediates, (2) selenium analogues of TTF, and (3) polymeric TTF compounds.