Scientia Sinica

No. 1 CHANG: .STUDIES ON FUSED RING SYSTEMS II 57

d-1-Keto-2-methyl-2-carbomethoxy-7-methoxy-l, 2, 3, 4, 9, 10, 11, 12-octahydrophenanthrenes (XI).—To a solution of the dimethyl ester of the /-acid in 60 ml of thiophene-free benzene, powdered sodium methylate prepared from 0.94 g of metallic sodium was added. The mixture was refluxed in an atmosphere of nitrogen. Within the first hour, plenty of the precipitated sodium salt of the keto ester separated out. After 4 hours, the mixture was cooled with ice and 10 ml of methyl iodide followed by 20 ml of absolute methyl alcohol was added. After the reaction mixture was left standing at room temperature for 10 hours, the precipitated sodium salt completely dissolved and a clear solution was obtained which was warmed on a water bath for half an hour. Upon cooling, the mixture was poured into 40 ml of water and acidified with acetic acid. The benzene layer was separated and the aqueous layer was extracted once with benzene. The combined benzene solu- tion was washed twice with water and dried with anhydrous magnesium sulfate. After the solvent was removed at reduced pressure, a yellow oil was obtained and amounted to 5.8 g which is probably a mixture of the diastereoisomeric d-keto esters.

By dissolving the yellow oil in a mixture of acetone-petroleum ether and placed in the ice box overnight, colourless crystals separated out. After being filtered and dried, it amounted to 1.4 g (first fraction); m.p. 110-113° (began to soften at the sides at 106°). After three recrystallizations from acetonepetroleum ether, it melted at 114-116°; yield, 0.67 g.

Rotation. A solution of 0.0655 g of the d-keto ester in 10 ml of absolute ethyl alcohol gave 4+0.583, [a]>+89°.

Analysis. Calcd. for CygH220.: Cx 7505 EE 7533" Found; C, 71.62; H, 7.43.

When the filtrate from the first fraction was concentrated to about half of its volume and left standing in the ice box, colourless crystals separated out, which, after being filtered and dried, amounted to 2.7 g; m.p. 75-89° (second fraction). The filtrate from the second fraction is the third fraction. At present, no work had been carried out on the separation of the diastereoisomers from the second and third fractions as yet. This kind of work will be carried out in the future.

Methyl d-1-Hydroxy-2-methyl-2-carbomethoxy-7-methoxy-1,2,3,4-9,10,11,12octahydrophenanthrene-l-acetate (XII) —To a solution of 0.4 g of d-keto ester (XI) (m.p. 114-116°) in 10 ml of pure benzene and 10 ml of absolute ether, 5 ¢ of granulated zinc (20 mesh) was added. The mixture was heated to reflux and 0.4 ml of methyl bromoacetate and 1 crystal of iodine were added with vigourous stirring. Within the first hour, colourless precipitate separated out from the reaction mixture. At every half-hour interval, 0.1 ml of methyl bromoacetate, 1 crystal of iodine and 2g of granulated zinc were added in