Intermediates epoxide solvolysis/rearrangement

Epoxidation with Solvolysis/Rearrangement of Intermediate Epoxide... 

Medium and large rings can be made via cationic intermediates which are usually generated by treatment of suitable precursors with acid. Reactions of this class are perchloric acid catalyzed rearrangements of bicyclo[n.l.0]alkan-2-ols (n > 5), solvolysis of the corresponding esters, boron trifluoride-diethyl ether complex catalyzed cleavage of epoxides, and tri-fluoroacetic acid catalyzed reactions of 7-(methylsulfanyl)bicyclo[n.l.0]alkanes. 

Methanesulfonates. The most common use of methanesulfonyl chloride is for the synthesis of sulfonate esters from alcohols. This can be readily accomplished by treatment of an alcohol with mesyl chloride in the presence of a base (usually Triethy-lamine or Pyridine). The methanesulfonates formed are functional equivalents of halides. As such they are frequently employed as intermediates for reactions such as displacements, eliminations, reductions, and rearrangements. Selective mesylation of a vicinal diol is a common method of preparation of epoxides." Alkynyl mesylates can be used for the synthesis of trimethylsilyl allenes. Oxime mesylates undergo a Beckmann rearrangement upon treatment with a Lewis acid. Aromatic mesylates have been used as substrates for nucleophilic aromatic substitution. Mesylates are more reactive than tosylates toward nucleophilic substitution, but less reactive toward solvolysis. 

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