Metal ion control of stereochemistry in the acetylation of calix[4]arene 1,3-diethers
Abstract
1,3-Dialkoxycalix[4]arenes 1–3 in Et2O give diacetylated derivatives in the fixed cone conformation with AcCl/NaH, whereas the stereoisomeric compounds in the partial cone structure are produced in high yield using AcCl/EtOTl.