Alkylthio special

This problem may, however, be a special case because the oxidation of pteridine alkenes in the presence of sensitive substituents such as alkylthio was shown to be possible using ligand-assisted catalysis with osmium tetraoxide or DMDO (Scheme 10). In the case of pteridine 65, a clean series of transformations to afford the pterin 66 was possible <20030BC664, 2005PTR53004/04>. However, if oxidation was carried out under moist conditions, the corresponding 2-oxopteridine (lumazine) was always obtained as illustrated by the conversion of 67 into the epoxide 68. 

Vinyl derivatives 147 which possess a /3-arylthio (or alkylthio) group tram to the leaving group are a special case which has been extensively investigated. The rate of l,2-diaryl-2-arylthiovinyl 2,4,6-trinitro-... 

One type of reaction of a,(3-unsaturated ketones with organomagnesium compounds deserves special comment. [3-Alkoxy or (3-alkylthio a, 3-unsaturated ketones tend to undergo 1,2-addition. This may be followed by elimination, as in the following example [82] ... 

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