Intramolecular Claisen Condensations: An Efficient Route Toward the Avermectins and Milbemycins

D. R. Williams and F. D. Klingler, Intramolecular Claisen Condensations:  An Efficient Route Toward the Avermectins and Milbemycins, J. Org. Chem. 1988, 53, 2134–2136.