Cyclohexyl mesylate

Two of the most commonly used sulfonyl chlorides are p-toluenesulfonyl chloride (abbreviated tosyl chloride, TsCl) and methanesulfonyl chloride (abbreviated mesyl chloride, MsCl). Treating ethanol with p-toluenesulfonyl chloride in the presence of pyridine gives ethyl p-toluenesulfonate (ethyl tosylate). Pyridine is added to catalyze the reaction and to neutralize the HCl formed as a by-producf. Cyclohexanol is converted to cyclohexyl methanesulfonate (cyclohexyl mesylate) by a similar reaction of cyclohexanol with methanesulfonyl chloride. 

Alcohol inversion. Elimination competes with S, 2 substitution in the inversion of secondary alcohols by the Mitsunobu reaction or by reaction of mesylates with cesium propionate or cesium acetate. Elimination in the inversion of cyclopentyl and cyclohexyl alcohols can be largely suppressed by reaction of the mesylate with cesium acetate (excess) and a catalytic amount of l8-crown-6 in refluxing benzene. Even inversion of an ally lie alcohol can be effected in moderate yield under these conditions (equation I). ... 

In a study of the reduction of primary neopentyl and cycloalkyl mesylates and tosylates, two groups showed that LiBEtaH in THF is superior to LAH and L-selectride in both rate and selectivity for reduction versus elimination. While cyclohexyl tosylate still gave 20% alkene, elimination was not seen for the cyclo-pentyl, -heptyl and -octyl esters. The lower rate for neopentyl systems was used to advantage in the selective reduction of (5) to (6) at 25 °C. In a more complex system, LiBEtaH reduction of (7 =... 

Scheme 69. Second-generation Grubbs catalyst applied to intermolecular enyne cross-metathesis for the preparation of anoUgnan. (Mes = Mesityl Cy = cyclohexyl Ms = mesylate.)...

Treatment of the diamide 77 with dibutyltin dichloride affords the 2,2-bis(2-[4(/ ),5(5)-diphenyl-1,3-oxazolinyl])propane 78, while successive reaction of 77 with mesyl chloride and aqueous ethanolic sodium hydroxide yields the diastereomer 79 <96TI3649>. The (+)- and (-)-forms of the chiral oxazoline 80 were used as ligands for palladium catalysed allylic amination reactions thus the acetate 81 and benzylamine gave the optically active amine 82 in excellent enantiomeric excess <97JOC55Q8>. The enantioselective catalytic alkylation of aldehydes RCHO (R = n-heptyl, Ph, cyclohexyl or PhCH=CH) with allyluibutyltin in the presence of chiral bis(oxazolinyl)zinc complexes, c.g., 83, leads to alcohols 84 in 40 6% enantiomeric excess <97TL145>. 

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