“…of liydrogen had been taken up, the reaction was stopped. The mixture was filtered, ancl the filtrate concentrated in Z ~U C U O to obtain a crude product which was chromatographed on silica gel to give the dihydro-ketone (10) (320 nig) as a light yellow oil, C1,H2, 0,Mf 220;m / e 220,177,162,149,121,107,55,and 43; vnlax. 1 725, 1415, 1 390, 1 380, and 1 363 cni-l; 6 0.93 and 1.12 (each 3 H, s), 1 67 (3 H , br s), and 2.03 (3 H, s ) ; A, , , , , , 212 nm (E 5 900).…”