A 2,2' : 6',2" : 6,6-tris(ethano)triarylborane was synthesized and its conformational analysis involving X-ray structure determination and molecular mechanics (MM2) calculation is examined.Co n fo r m at i o n s a n d conformation a 1 isom e ri za t i o n of t r i ar y 1boranes have received considerable interest. Dynamic NMR studies of several triarylboranes having relatively bulky substitutcnts on the aryl groups have been investigated by Mislow and coworkers. They showed stereoisomerization of these propeller type of compounds proceeds viu two ring flip mechanism with activation barrier of 14-18 kcal mol (1 cal = 4.184 J).' We have recently reported the synthesis and s t e re oi so me r iza t ion of e t h a n obridged t r i ar y 1 bo r a n e s la-c and succeeded in resolving l b and c into optically pure form for the first time in solution at room temperature.2 In this paper we report the synthesis and conformational analysis of the symmetrically bridged 2,2' : 6',2" : 6".6-tris(ethano)triarylborane 2 which is the ultimate compound in this series of c t h a n obridged t r i ar y l bor a n e s .

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Anemia-inducing substance (AIS) appears in plasma as cancer progresses. In this study, a non-coated charcoal column was used to remove AIS from the cachectic plasma obtained from patients with advanced cancer. AIS could be completely removed by 6 cycles of adsorption using this column. Similar data were obtained in an experiment using VX-2-transplanted rabbits. These observations raised the possibility that plasmapheresis with a non-coated charcoal column may be available as a new means of immunotherapy for advanced cancer.

Tris(dimesitylboryl)benzene and 1,3-bis(dimesitylboryI)benzene were synthesized and their conformational analysis including X-ray structure determination of the former was studied; electrochemical properties of these compounds were also examined.

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