In a typical experiment, to a well stirred suspension of NaH in HMPA, under argon, was added dropwise a solution of the silyl ether in HMPA (in cases where the silyl ether is not soluble in HMPA a saturated solution in THF can be added), and the mixture was allowed to stir at 25OC. In general 2 equiv. of NaH were used per equiv. of the silyl ether (additional NaH was used to account for the free hydroxyl groups wherever necessary). ... 1,2,4,6, and ll), were ...
