Water covalent oxide reactions with

The action of sulfur nucleophiles like sodium bisulfite and thiophenols causes even pteridines that are unreactive towards water or alcohols to undergo covalent addition reactions. Thus, pteridin-7-one smoothly adds the named S-nucleophiles in a 1 1 ratio to C-6 (65JCS6930). Similarly, pteridin-4-one (73) yields adducts (74) in a 2 1 ratio at C-6 and C-7 exclusively (equation 14), as do 4-aminopteridine and lumazine with sodium bisulfite. Xanthopterin forms a 7,8-adduct and 7,8-dihydropterin can easily be converted to sodium 5,6,7,8-tetrahydropterin-6-sulfonate (66JCS(C)285), which leads to pterin-6-sulfonic acid on oxidation (59HCA1854). 

Alkaline earth oxides, heat of reaction with water, 382 Alkaline earth sulfates, K,r, 382 Alkanes, 341 naming, 338 Alkyl group, 336 Alloys, 309 Alnico, 406 copper, 71, 309 covalent bonds, and, 305 gold, 71... 

Bis(tributyltin) oxide, BtijSnOSnBuj, is a high-boiling oil, bp 180°C/2 mm, with a penetrating, unpleasant, sweetish smell. It is readily available. Mixing with an alcohol R-OH gives a tributylstannyl ether according to Eq. (5), a reversible reaction that may be drawn to completion by azeotropic removal of water. These ethers are moisture-sensitive. They are undoubtedly covalent derivatives, yet their reactions with electrophiles are, broadly speak-... 

The structure of H2SO4 is shown in the margin. In this case, the strong, covalent 0—S bonds remain intact and the H—O bonds break to produce protons. Other common covalent oxides that react with water to form acidic solutions are sulfur dioxide, carbon dioxide, and nitrogen dioxide, as shown by the following reactions ... 

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