1-Naphthylmethyl and 1-naphthylmethoxymethyl protecting groups: New members of the benzyl- and benzyloxymethyl-type family

Abstract 1-Naphthylmethyl (NAP I ) and 1-naphthylmethoxymethyl (NAPOM I ) protecting groups were developed as new members of the benzyl- and benzyloxymethyl-type family. NAP I and NAPOM I can be introduced under conventional conditions, such as NAP I Br/NaH/room temperature (rt), or NAPOM I Cl/ i -Pr 2 EtN/rt. They can also be removed under conventional conditions, e.g., by dichlorodicyanobenzoquinone (DDQ)- or ceric ammonium nitrate (CAN)-mediated oxidation, or by hydrogenolysis. The specific advantages of these new protecting groups are: i) a less costly synthesis of NAPOM I Cl compared to NAPOM II Cl, ii) the possibility to remove NAPOM II selectively in the presence of NAPOM I by DDQ-mediated oxidation, and iii) the compatibility with strong acids even in the presence of hard nucleophiles.