Unless otherwise stated H NMR C NMR

2. Experimental
2.1. Materials
?-Caprolactone was purchased from Sigma–Aldrich (99%) and distilled over calcium hydride Nocodazole under reduced pressure. Ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF6] 1, 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide [bmim][NTf2] 2, 1-butyl-3-methylimidazolium tetrafluoroborate [bmim][BF4] 4, 1-butyl-3-methylimidazolium trifluoromethanesulfonate [bmim][SO3CF3] 5, 1-butyl-3-methylimidazolium chloride [bmim][Cl] 6 (Fig. 1) were purchased from Sigma–Aldrich and used as received without further purification. The benzylalcohol was purchased from Sigma–Aldrich and distilled in vacuo. The ionic liquids 1-methyl-3-methylimidazolium dimethylphosphate [Memim][PO4Me2] 3 (Bradaric et al., 2003) and 1-methyl-3-methylimidazolium hexafluorophosphate [Memim][PF6] 7 and, 1-isopropyl-3-methylimidazolium hexafluorophosphate [iPrmim][PF6] 8 ( Kumar and Jain, 2012) were synthesized following the cellulose literature.
2.2. Instrumentation