... (19) We are grateful to Professor Dale Boger, of Scripps Research Institute, for providing an authentic sample of 22. Page 4. Enynones in Organic Synthesis Scheme 5 R R P O 42.,b "xh P : P H 43r,b(H+) '-k + %[ ' a O ti + l Mr,b J. Org. Chem., Vol. 60, No. 2, 1995 379 Scheme 7 ...