Rearrangements polytopal

Bismuth heterocycles, 1, 539-561 Bismuthiol I metal complexes, 6, 565 IR spectra, 6, 552 ring structure, 6, 561 structure, 6, 557 Bismuthiol II metal complexes, 6, 565 IR spectra, 6, 552 Bisnorisopenicillin, 7, 332, 333 Bisnorpenicillin V, 7, 331 Bis( l,3,4-oxathiazol-2-ones) applications, 6, 945 Bisoxiranes synthesis, 7, 42 Bi(spiroisoxazolines) synthesis, 6, 108 Bi(spirophosphoranes) polytopal rearrangements, 1, 529 reactions, 1, 535 Bispyranones synthesis, 3, 793 a,oj-Bispyranones, alkylene-irradiation, 3, 678... 

Polythia six-membered ring systems, 3, 1039-1086 Polythiazides as diuretic, 1, 174 Polythiiranes, 7, 182 Polytopal rearrangements phosphoranes, 1, 529-530 rules, 1, 530 Polyurethanes curing agents... 

By contrast to its spiro sulfurane analog. 31 in a CDCI, and nitrobenzene solution at room temperature displays a rapid polytopal rearrangement that results in the averaging of the diastereotopic protons of the methylene groups. The increase in the frequency of the polytopal rearrangements on going from sulfuranes to telluranes is in accord with theoretical predictions (77ZOB2011). 

Based on the XH DNMR data1232, it is suggested that both diastereomers with either a cis or trans arrangement of the Br atoms are present in solution of dibromides 560a-b. The polytopic rearrangement in dihalides (L")2GeX2 is discussed below. 

The regular permutational isomerizations (or regular polytopal rearrangements) take place without the rupture of bonds, i.e., with preservation of neighborhood relationships. 

The irregular permutational isomerizations (or irregular polytopal rearrangements) occur with fission and re-formation of bonds. 

Westheimer FH (1980) The polytopal rearrangement at phosphorus. In Mayo E (ed) Rearrangements in ground and excited states, vol 2. Academic Press, New York, p 229... 

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