$C{H_2} = C{H_2}\xrightarrow{{{O_2}/Ag}}X\xrightarrow{{473\,{\kern 1pt} K}}Y$
$2PhCHO \xrightarrow{{:\mathop O\limits^ \ominus H}}PhC{H_2}OH + PhC\mathop {O_2^ \ominus }\limits^{.\,\,.\,\,} $
ધીમો તબબકો :