Scientia Sinica

58 SCIENTIA SINICA Vol, V

turn. Altogether four additions were made and the reaction time was two hours and a half. Upon cooling, the reaction mixture was poured into 10 ml of ice water and a few drops of acetic acid were added to dissolve the addition product produced in the reaction and mixed with the zinc. The zinc was washed twice with a small amount of benzene. The ether-benzene layer was separated from the aqueous layer and washed once with N ammonium hydroxide and twice with water. After being dried with anhydrous magnesium sulfate, the solvent was distilled off at reduced pressure and light yellow oil was obtained; yield, 0.42 g. This oily product, upon recrystallization from methyl alcohol, formed colourless needles; m.p. 86-88° (began to soften at the sides at 83°).

Rotation. A solution of 0.022 g of the hydroxy ester in 10 ml of anhydrous ethyl alcohol gave e+0.25, [a]$+113.6°. ,

Analysis. Calcd. for Ca;HO,: C, 67.00; H, 7.50. Found: C, 67.14; ES, 7225:

Dimethyl Ester of d- y-(6-Methoxy-2-carboxy-1,2,3,4-tetrahydro-1-naphthyl)butyric Acid (XIV).—To a suspension of 6 g of d-acid (XIII) (m.p. 168-170° ) in 20 ml of anhydrous ether, an ethereal solution of diazomethane prepared from 20 g of N-nitroso-B-methylaminoisobutyl methyl ketone"! was added. After the mixture was left standing at room temperature for an hour, the ether was blown off with air and colourless oil was obtained as residue which was used directly for the following experiment.

J-1-Keto-2-methyl-2-carbomethoxy-7-methoxy-l, 2, 3, 4, 9, 10, 11, 12-octahydrophenanthrenes (XV).—The dimethyl ester of the d-acid obtained from the previous experiment was cyclized by Dieckmann reaction followed by methylation according to the method described for the preparation of the d-keto ester (XI). The product from this reaction amounted to 5.7 g of yellow oil which is probably a mixture of the diastereoisomers of the /-keto ester.

By dissolving the yellow oil in a mixture of acetone and petroleum ether and leaving the solution in the ice box overnight, colourless crystals separated out. The crystals were filtered off and dried and amounted to 1.7 g; m.p. 108-112° (began to soften at the sides at 100°; first fraction). After four recrystallizations from acetone-petroleum ether, this fraction of the keto ester

melted at. 114-116°; yield, 0.74 g.

Rotation. A solution of 0.047 g of the /-keto ester in 10 ml of absolute ethyl alcohol gave a—(0.425, [a]?—90.4°.

Analysis. Calcd. for CygHooOu: C, 71.50; He7e33: Found: C, 71.56; _-H, 7.27.

After the filtrate from the first fraction was concentrated to about half