Addition Reactions of Unsaturated Sulphones

Kobayashi, H. Minato, M. Kojima, and N. Kiunigata, Bull. Chem. Soc. Japan, 

Thebaine acts as diene component in Diels-Alder reactions with methyl vinyl sulphone or divinyl sulphone. 1 1 Adducts are formed in both cases. The analgesic properties of some elaboration products of these adducts, e.g. (136), equal the potency of codeine. Cyclopentadiene adds 

Reactions at a jSy-alkynyl function in an acetylenic sulphone (140) give products indicating the influence of the sulphonyl group, e.g. the formation of the vinyl sulphone (141), which gives j8-keto-sulphones through cleavage of the oxetan ring at different points on acid hydrolysis. 

Acylation of ethyl carbamate with MeSOgCHj COaH gives MeSOj-CH2 C0 NHC02Et, used for the synthesis of 5-methanesulphonyluridine by ethoxymethylenation followed by condensation with 2,3,5-tri-O-benzoyl ribofuranosylamine.  

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