CHEMOSELECTIVE MONOALKYLATION OF 5-TRIFLUOROACETAMIDO- AND 5-ACETAMIDO-1-PENTANOL DERIVATIVES VIA N,O-BISDEPROTONATION. QUANTITATION OF EVOLVED H2 AS A PROBE OF ANION FORMATION.

Article abstract of DOI:10.1016/0040-4039(95)00280-P

Measurements of H2 evolution revealed that neither 5-trifluoroacetamido-1-pentanol (1) nor 5-acetamido-1-pentanol (6) underwent complete bisdeprotonation upon treatment with excess NaH in THF, thereby accounting for the unexpected course of subsequent alkylations with carbohydrate-derived triflates 2 and 7.These studies in turn led to an effective protocol for generation of N,O-dianions from 1 and 6; as anticipated, the former chemoselectively furnished O-alkylation products with triflates 2 and 15.