Deuterated compounds Sulfuric acid

Sulfonimidothiazolines, 317, 318 Sulfonyl halides, with 2-aminothiazoles, 69 Sulfur (Sg), in synthesis of, A-4-thiazoline-2-thione, 373 Sulfur compounds, 69 Sulfuric acid, with alcohols, 38, 47, 80, 90 in bromination, 77 dealkylation by, 39 deuterated, 92 diazotization with, 66 in nitrations, 72 rearrangements in, 73, 113 Sulfuryl chloride, 432 Symbiotic behavior, see HSAB theory Symmetry. C2v and C2p, 120 Synthetic fibers, 154... 

The hydrates are relatively stable but the hemiacetals seem to be in equilibrium with the parent ketone. The latter feature is supported by the fact that hemiacetals slowly exchange the alkoxy moiety on standing with an appropriate alcohol. This exchange process is accelerated by the addition of acid. Compound 4 exchanged 66% of the methoxy group for trideuteromethoxy within 1.5 hours when treated with methanol- f4 in the presence of sulfuric acid. On the other hand, in the absence of acid, 50% of the deuterated methyl hemiacetal is obtained on heating at 40°C for 45 hours. 

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