Facile protection of phenols and hydroxypyridines: key components of natural products--a new pathway to orellanine.

The (1,3,6-trioxa-heptyl) aromatic compounds are easily prepared from various phenols and hydroxypyridines. Protection by 2-methoxyethoxymethyl chloride (MEM-Cl) was achieved by phase transfer catalysis with Aliquat 336, subsequent removal of the protecting group was completed with Amberlyst 15. The 2-bromo-3-hydroxy-pyridine 3o constitutes the appropriate starting material for the synthesis of orellanine, the most potent nephrotoxin found in some Cortinarius mushrooms species.