New Application of Burgess Reagent in its Reaction with Epoxides

Abstract

Burgess reagent, (methoxycarbonylsulfamoyl)triethyl- ammonium hydroxide, usually used for the dehydration of second- ary or tertiary alcohols, was successfully employed in the formation of sulfamidates from the corresponding epoxides. It was further shown that the same reaction with aromatic epoxides results in the formation of seven-membered ring systems. In 1970 Burgess and coworkers described a new and very mild method for the dehydration of secondary and tertiary alcohols to the corresponding olefins using the inner salt of (methoxycarbonylsulfamoyl)triethylammonium hy- droxide (2, Burgess reagent). 1 The proposed mechanism involves the attack of the hydroxyl functionality onto the sulfur followed by syn-elimination of the intermediate sulfamate (3), Scheme 1. The Burgess reagent has been used primarily for the dehy- dration of secondary and tertiary alcohols, 2 and its use has figured in the total synthesis of important natural prod- ucts, for example in Rigby's syntheses of narciclasine 3 and cedrene, 4 Nicolaou's synthesis of efrotomycin, 5 Uskokovic's synthesis of pravastatin, 6 and Holton's syn- thesis of Taxol ® . 7 Further applications have been report- ed, for example nitrile formation from primary amides, 8 isocyanide formation from formamides, 9 and synthesis of urethanes from primary alcohols. 1,10 Wipf developed a