—Not yet—� They use protecting groups that respond to different chemical signals. 4-Methoxybenzyl chloride installs one of the classics: the p-methoxybenzyl, or PMB, group.
An alcohol can temporarily become: R-O-CH2-C6H4-OCH3 Now the OH is hidden. But PMB has a useful trick. Compare it with an ordinary benzyl protecting group. The structures are almost identical. PMB simply adds one methoxy group to the aromatic ring.
Global Chemical Database