Esterification of five-membered cyclic phosphinic acids under mild conditions using propylphosphonic anhydride (T3P®)

1-Hydroxy-phospholene 1-oxides (1 and 3) and 1-hydroxy-phospholane oxides (5 and 7) undergo fast and efficient esterification with a series of alcohols, at room temperature, in the presence of 1.1 equiv of propylphosphonic anhydride (T3P (R)). (C) 2013 Elsevier Ltd. All rights reserved.