Acknowledgment.-This research was supported by the Sational Science Foundation to whom the authors are deeply indebted. ... Research Laboratories, Tennessee Eastman Company, Division of Eastman Kodak Company, Kingsport, Tennessee Received July $1, 1966 ... A new trimer of dimethylketene, 5-hydroxy-2,2,4,4,6-pentamethyl-3-0~0-5-heptenoic ... The mechanism of its formation is discussed, and new proposals are set forth to rationalize more com- ...