Cytosine sulfonate to uracil sulfonate: conversion of cytosine sulfonate to uracil sulfonate leads to alkali desulfonation
. Uracil sulfonate is converted into uracil.
1 reaction proceeds with sulfonation of polyethylene with substitution of S[O.sub.3]H group on carbon atom, and then desulfonation
due to abstraction of hydride ion from the polyethylene chain.
Chan, "One-pot synthesis of sulfonyl (E)-stilbenes by nitrobenzene-mediated dimerizative desulfonation
of benzylic sulfones," Tetrahedron, vol.
The first approach was to block the desulfonation
of E1S by offering nonhydrolysable E1S analogues, for example, sulfates of the flavonoid daidzein.
The extracted DNA is then subjected to sodium bisulfite conversion, which requires denaturation of genomic DNA, deamination of unmethylated cytosines with a high sodium bisulfite concentration, and desulfonation with a strong base.
Apart from being a single-tube process, this technique has the unique feature of combining deamination and desulfonation, a simplification from the conventional approach, which requires binding and washing steps between these 2 processes.
Minimizing binding and washing steps by combining deamination and desulfonation can further improve efficiency.
While the addition product 21 undergoes relatively faster desulfonation
to 22, the acetyl protected 23 on the other hand is quite stable (Scheme 6).
The latter effect was attributed to a competing desulfonation reaction that occurs for arylsulfonic acids in an acidic medium .
This is similar to what was observed for SPEEK and can be attributed to desulfonation .
Then, the term desulfonation (or hydrolysis of [approximately]S[O.sub.3] group) is commonly used (12, 13) to describe the reverse process.
Sulfonation itself prefers high concentrations of sulfuric acid; however, partial desulfonation was observed even in the most concentrated sulfuric acid (6).