Ethyl alkynyl ethers: A convenient ketene source for lactone formation
摘要:
A convenient and general method for the preparation of lactones of varying size via the intramolecular trapping of a ketene has been developed. Simple thermolysis of various ethoxy acetylene derivatives at 150-degrees-C for 2 hours produced the desired compounds in yields ranging from 30%-75%. The addition of tri-n-butylamine was required to achieve reasonable yields for medium and large rings.