Poly-halo compounds

Traditionally, this radical addition reaction has been used for the preparation of new poly halo organic compounds by reaction of simple polyhalo alkanes with alkenes689 698. The products from these reactions have often been used as key intermediates for the synthesis of heterocyclic compounds690. In some cases it has been found that metal complexes significantly speed up reactions and/or increase yields. 

The reductive photodehalogenation of aryl halides has been actively investigated in recent years. Special attention has been given to (poly)halobenzenes and (poly)halo-biphenyls. The reactions are of interest in view of their mechanisms, and because of the importance of chlorinated aromatic hydrocarbons as environmental pollutants and the possibility of their photoinduced degradation. The photochemistry of aryl halides and related compounds in general14 and the photochemistry of polyhaloarenes in particular18 have been reviewed. 

Various derivatives of fiuan and pyran are cleaved to give open-chain di- and poly-functional compounds. Fission to give dihalides, halo alcohols, and halo esters is described elsewhere (method 34). Hydrogenation and hydrogenolysis reactions lead to hydroxy compounds, as in the preparation of 5-hydroxy-2-pentanone and 1,4-pentanediol from methyl-... 

The mutual chemistry of plastic containers and food products must be considered for any proposed application. There is continuous physical and chemical activity at the interface between the food product and the container. The type and extent of this activity determines whether or not the plastic container can successfully hold and protect the food product. However, the U.S. Food and Drug Administration and the American public are increasingly suspicious of all plastics, particularly the halo-genated compounds. The recent ban (April 1973) on poly(vinyl chloride)... 

The red algae (Rhodophyta) are the most prolific sources of halogenated organics in the marine environment, and this topic was recently reviewed (Fenical, 1975). At least six orders, representing some ten families of red algae are now known to produce a wide variety of structure types from halo-methanes (C,) to halogenated products derived from squalene (C30). Within this group are aromatic and acyclic compounds produced from acetate (poly-ketide) biosynthesis and monoterpenes (Cio), sesqui- (Cu) and diterpenoids (C2o)- The structures of well over 200 compounds have now been firmly established. 

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