During a recent investigation of preparative routes to functionalized aza crown ethers,'we observed exclusive N-benzyl group cleavage when monoaza crown 1 reacted with hydrogen in the presence of palladium on activated carbon (Pd/C) catalyst. Since it is generally assumed that 0-debenzylation takes place with greater ease than does removal of an N-benzyl group, 2s3 this result was totally unexpeded. Also, selective cleavage of the 0 ...
