Synthesis of fluorinated hemiketals from the reaction between alcohols and hexafluoroacetone

The alcohols, phenoxyethanol (a) and (2-hydroxymethyl)tetrahydrofuran (c) were treated with hexafluoroacetone (HFA) to give the corresponding hemiketals 2-(2'-phenoxyethoxy)-1,1,1,3,3,3-hexafluoropropan-2-ol (b) and 2-(2'-tetrahydro-pyranylmethoxy)-1,1,1,3,3,3-hexafluoropropan-2-ol (d), respectively. Also, the protected nucleosides 2',3'-O-isopropylideneuridine (e) and 3,3'-N,O-dibenzoyl-thymidine (g) were treated with HFA to give the corresponding hemiketals 5'-O-(1 -trifluoromethyl-1-hydroxytrifluoroethyl)-2',3'-O-isopropylidene-uridine (f), and 5'-O-(1-trifluoromethyl-1-hydroxytrifluoroethyl)-3,3'-N, O-dibenzoyl-thymidine (h), respectively. (C) 2000 Elsevier Science S.A. All rights reserved.