| 摘要 |
<p>1,259,674. Substituted cyclopentanones. AMERICAN HOME PRODUCTS CORP. 10 Jan., 1969 [1 Feb., 1968; 4 Oct., 1968], No. 18718/71. Divided out of 1,259,673. Heading C2C. The invention comprises novel substituted cyclopentanones of the Formula I wherein R<SP>1</SP> and R<SP>2</SP> are C 1-20 alkyl radicals optionally substituted by carboxy, carbo-(C 1-6 alkoxy), hydroxy, tetrahydropyranyloxy or C 1-7 acyloxy, 5 - (6 - methoxy - carbonyl) - 4 - (3 - tetrahydropyran - 2<SP>1 </SP>- yloxyoctyl) - cyclopent - 2 - ene - 1- one and 5 - (6 - carboxyhexy) - 4 - (3 - tetrahydropyran - 21 - yloxyoctyl)cyclopent - 2- en-1-one. The compounds of Formula I above are prepared by epoxidizing the corresponding 4 - R<SP>1</SP> - 5 - R<SP>1</SP> - 2 - cyclopenten - 1 - ones, which are obtained by cyclizing levulinaldehydes of the formula with bases. 5-(6-Carboxyhexyl)-4-(3-tetrahydropyran - 2<SP>1</SP>- yloxyoctyl) - 2 - cyclopenten - 1- one and its methyl ester are obtained by cyclizing 2 - (3 - tetrahydro - pyran - 2<SP>1</SP>- yloxy) - 3 - (6 - methoxycarbonylhexyl)- levulinaldehyde with sodium hydroxide. 4 - (3 - Hydroxyoctyl - 5 - (6 - carboxyhexyl)- 2-cyclopenten-1-one is made by treating the corresponding tetrahydropyranyl ether with hydrochloric acid. 2,3 - Dimethyllevulinaldehyde is obtained by ozonolysis of 3,4-dimethyl-5-heptene-2-one, obtained by heating a mixture of water, barium hydroxide and ethyl 2 - methyl - 2 - (1 - methyl- 2-butenyl)-acetoacetate, which is made by condensing ethylα-methylacetoacetate in the presence of sodium hydride with 4-bromo-2-pentene resulting from the bromination of 2-penten-4-ol. The following aldehydes are also obtained by ozonolysis of appropriate compounds: 2,3-din - eicosyllevulinaldehyde, 2 - n - eicosyl - 3 - (6- hexyloxyearbonylhexyl)- levulinaldehyde, and 2 - (3 - acetoxy - octyl) - 3 - octyllevulinaldehyde.</p> |
