Ring-Opening of Lactones and Cyclic Carbonates with Bromo- or Iodotrimethylsilane

✍ Scribed by Dr. Hans R. Kricheldorf

• Publisher: John Wiley and Sons
• Year: 1979
• Tongue: English
• Weight: 238 KB
• Volume: 18
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.197906891

✦ Synopsis

of basic aluminum oxide (activity I, Merck). After 6 hours' stirring at room temperature the aluminum oxide is filtered off and extracted several times with chloroform. After removal of the solvents the isomeric mixture (76) is obtained quantitatively as a yellow oil, which can be separated by chromatography on silica gel [ 'H-NMR (ChD6): 6 = 6.09 for the one isomer and 6.83 for the other (t, J = 7 Hz; d, J = 3 Hz; 4H)], though this is not necessary for the next step, i.e. for the synthesis of (Sb).

Synthesis of (86): A solution of cerium(1v) ammonium nitrate (9.0 g) in acetone (120 ml) is added dropwise (ca. l h) to a solution of (76) (1.0 g) in acetone (50 ml) at 0 "C. The mixture is stirred for 0.5 h, treated with 200 g of ice and extracted twice with ether. The extracts are evaporated down and the residue taken up in ether again, washed with water and dried over MgS04. After removal of solvent the residue is dissolved in hexane and filtered through a small amount of Florisil: yield 0.42 g (95%) pure (86).