4306 by suction filtration and was washed with several portions of ether and methanol, and the combined filtrate and washings were evaporated. Molecular distillation of the residue gave 0.76 g (76%) of yellow oil; glpc analysis of this material on column A at 225" showed the p-atlantone (retention time 14.8 min) had been converted to a product with retention time 20.3 min. Purification of the product by preparative glpc on column C at 225" followed by molecular distillation yielded (+)-a-atlantone (27) as a yellow oil, bp (bath) C=CH-), 1675 ( > e o ) ,1625 (conjugated >C= CH-), 1113, 1060,and 878 cm-l; uv,,,(CH30H) 269 mp ( E 21,000 i 1100); nmr (CDC13) 7 4.04 (broadened s, 2 H, >C=CHCOCH=C
