A Convenient Method for Converting Hydroxyacetophenones into Their Ethylene or Trimethylene Acetals
作者:Tsuneo Sato、Fumiaki Ono、Hirotaka Takenaka、Toshikazu Fujikawa、Masaki Mori
DOI:10.1055/s-0028-1088025
日期:2009.4
Various types of hydroxyacetophenones are efficiently converted into the corresponding ethylene acetals in the presence of ethane-1,2-diol, triisopropyl orthoformate, and a catalytic amount of cerium(III) trifluoromethanesulfonate under mild reaction conditions. The homologous trimethylene acetals can be also prepared in the same way.
A green procedure for the protection of carbonyl compounds catalyzed by iodine in ionic liquid
作者:Yi-Ming Ren、Chun Cai
DOI:10.1016/j.tetlet.2008.09.088
日期:2008.12
Aldehydes and ketones are protected with ethylene glycol in the presence of a catalytic amount of iodine in PEG ionic liquid (IL 400) under mild conditions to afford the corresponding ketals in good yields. The recovery of iodine is facilitated by the ionic liquid. The recovered catalyst was reused six times with consistent activity. (C) 2008 Elsevier Ltd. All rights reserved.