... Structure II is assigned to this product on the basis of spectra] evidence and chemical evidence to be presented. Thus, hydrolysis of the ester II gave a crystalline acid (III) which was converted to ' W. von E. Doering and T. Mole, Tetrahedron 10, 65 (1960). * PS Skell and RM Etter, Proc. Chem. Soc. 443 (1961). ... Chem. Soc. 78, 4496 (1956). 4 P. Yates,7. Amer. Chem. Soc. 74, 5376 (1952). 1029 1030 RR SAUERS and PE SONNET + NzCHCO?C;H5 FIG. ...