... rend., 249, 970 (1959). (3) N. P. Buu-HOY, N. D. Xuong, and BK DiCp, J. Org. Chem., 26, 1673 (1961). ... The organic layer waa then collected, washed with water, and dried over sodium sulfate, the ether was distilled, and the residue vacuum-fractionated twice. ...