Rearrangement reversibility

It now seems definitely proved that the thiothiophthene (86) rearranged reversibly to a thiophene (87) under the influence of alkali and not to a thiepin derivative, The dimethyl ether of (87) has been oxidized to 4-methylsulfonyl-2-thiophenecarboxylic acid (88)... 

Upon heating the enediyne la rearranges reversibly to the 1,4-benzenediyl diradical 2a, which in its turn can rearrange to the enediyne lb or—in the presence of a hydrogen donor (e.g. cyclohexa-1,4-diene)—react to the aromatic compound 3a. 

The [111] plane the most closely packed (six-coordinated) surface of the fee structure and is very stable. The five-coordinated B5 structures may have [110] or [311] configuration (137). The four-coordinated [100] plane rearranges reversibly to a six-coordinated structure (138). Carbon-platinum interactions cause faceting of the [100] plane, giving rise to the formation of [211] or [311] structures (139). 

If our proposal that allylic sulfoxides rearrange reversibly to sulfenate esters is correct, then, if we make the sulfenate ester by another route, it too should rearrange to an allylic sulfoxide—and indeed it does. The sulfenate ester arising from reaction of allylic alcohols with PhSCl (phenylsulfenyl chloride) cannot be isolated instead, the allylic sulfoxide is obtained, usually in very good yield, and this method is often used to make allylic sulfoxides. 

Biphenylenyl) - 3 - acetyl - 5-methyl-2,3-dihydro-1,3,4-oxadiazole (84) rearranges reversibly on warming to give the 2-(9-fluorenyl)-2V-diacetylhydrazone (85). 2-(Biphenylenyl)-3-benzoyl-5-methyl-2,3-di-... 

Stereoisomerization cis-78a and trans-79a accept an electron to give the diphenyl-cyclopropane radical anions cis-78a and trans-79a which rearrange reversibly into the trimethylene radical anion 80 a. The stereoisomerization takes place at the trimethylene radical anion stage. The reversible formation of 80a in THF is noteworthy because the trimethylene radical anions 46 and 47 have been formed irreversibly, however in this case in NH3, see Scheme 3, page 12. 

MISLOW-BRAVERMAN-EVANS Rearrangement Reversible 2,3-sigmatropic rearrangement of allylic sulfoxides to allyl sulfenates which are cleaved by phosphites or thiols to allylic alcohols (see 1st edition). 

MISLOW BRAVERMAN - EVANS Rearrangement Reversible 2,3- sigmatropic rearrangement of alyfc sulfoxides to alyl sulenates which are cleaved by phosphites to allyNc alcohols. 

The acetal 37 of (l,2,4/3)-cyclopentanetetrol predictably reacts, by hydride abstraction, with triphenylmethyl fluoroborate to give the fluoroborate salt of the ion 39. The ion 39 can rearrange reversibly to give the ion 40, and, subsequendy, the ion 41 this rearrangement. 

Brook rearrangement, reverse 44, 514 Bruylants-type reaction 44, 899 1,3-Butadienes... 

It has been established that polysulfide polymers in the preseix% of sodium polysulfide are constantly rearranging reversibly ... 

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