Background: Ease of preparation and alkaline stability of methoxymethyl (MOM) makes it
an important hydroxyl protecting group. A number of methods are available for the deprotection of
MOM. Though the methods are good in general, they use solvents, require prolonged reaction time
and tedious work up. A solvent free, solid phase, fast deprotection of MOM has been developed and is
the major theme of this paper.
Methods: A mixture of MOM protected compounds and pTSA is triturated in a mortar (5 min) and left
at room temperature for 30 min. On addition of water (4oC), pTSA, methanol and formaldehyde dissolved
leaving the products as precipitates.
Results: A series of different MOM ethers were deprotected by this method in good to excellent yield
(85-98%). The compatibility of MOM in the presence of other protections such as methoxyl, benzyl, ester,
amide, allyl and lactone was also established. Acetate protection is not stable under these conditions.
Conclusion: An efficient, selective and high yielding deprotection MOM groups by pTSA under solvent
free condition is described. The process is environment friendly since no solvent was used in the
deprotection process. The reaction conditions are mild and should be useful for the deprotection of
MOM derivatives of complex and labile molecules.