SPIRO[4.5]DECANE-7,9-DIONE

A mixture of 1 -cyclopentylidene-propan-2-one (1 g, 9.4 mmol) and diethyl malonate (1 .75 g, 1 1 mmol) is added dropwise to a slution of sodium methoxide prepared by dissolving sodium (0.25 g, 1 1 mmol) in MeOH (3 ml_). The mixture is heated to reflux for 2 h, then a hot solution of barium hydroxide (1 1 .23 g, 73 mmol) in 100 ml_ of water is added and the mixture is refluxed for 24 h, then neutralized to pH 6 with diluted hydrochloric acid while still hot and filtered. The filtrate is cooled and acidified to pH 1 with diluted hydrochloric acid, refluxed for 15 min, filtered while hot and then cooled. The formed precipitate is filtered, washed with water and dried to give 0.87 g (56percent) of spiro[4.5]decane-7, 9-dione.Step ii: spiro[4.51decane-7, 9-dione A mixture of 1 -cyclopentylidene-propan-2-one (1 g, 9.4 mmol) and diethyl malonate (1 .75 g, 1 1 mmol) is added dropwise to a slution of sodium methoxide prepared by dissolving sodium (0.25 g, 1 1 mmol) in MeOH (3 ml_). The mixture is heated to reflux for 2 h, then a hot solution of barium hydroxide (1 1 .23 g, 73 mmol) in 100 ml_ of water is added and the mixture is refluxed for 24 h, then neutralized to pH 6 with diluted hydrochloric acid while still hot and filtered. The filtrate is cooled and acidified to pH 1 with diluted hydrochloric acid, refluxed for 15 min, filtered while hot and then cooled. The formed precipitate is filtered, washed with water and dried to give 0.87 g (56%) of spiro[4.5]decane-7, 9-dione.Step ii: spiro[4.51decane-7, 9-dione To a 250 mL round bottom flask, was added methanol (3 mL). To the same flask, sodium metal (0.25 g, 0.008 mol) was added portion wise. The reaction mixture was stirred at room temperature until all sodium metal had dissolved. To the same flask, 1 -cyclopentylidenepropan- 2-one (1 g, 0.008 mol) and diethyl malonate (1.75 g, 0.0096 mol) were added drop wise. The resulting mixture was stirred at reflux temperature for 2 h. To the reaction mixture, a solution of barium hydroxide (11.23 g, 0.064 mol) in water (100 mL) was added. The hot reaction mixture was stirred at reflux temperature for 24 h and acidified to pH 6.0 with dil. hydrochloric acid to get the suspension. The hot suspension was filtered to get a clear filtrate. The filtrate was acidified to pH 1.0 with dil. hydrochloric acid and stirred at reflux temperature for 15 min. The hot reaction mixture was filtered to get the filtrate. The filtrate was cooled to room temperature and extracted with ethyl acetate. The organic layer was separated, washed with brine and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure to get the title compound [0.65 g, 46 %]. NMR (300 MHz, CDC13): delta 3.63 (s, 2H), 2.61 (s, 4H), 1.73 - 1.67 (m, 4H), 1.49-1.45 (m, 4H); LC-MS: 167.2 [M+H]+.

Molecular Weight:166.22
XLogP3:1.7
Hydrogen Bond Acceptor Count:2
Exact Mass:166.099379685
Monoisotopic Mass:166.099379685
Topological Polar Surface Area:34.1
Heavy Atom Count:12
Complexity:206
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes