| 摘要 |
<p>1336326 Cyclopentene derivatives F HOFFMANN-LA ROCHE & CO AG 8 July 1971 [10 July 1970] 4109/73 Headings C2P and C2C The invention comprises compounds of Formula I: where X<SP>11</SP> is acetyl (the carbonyl group of which may be ketalized), ethyl or methyl, Y is aryl or di-(C 1-6 alkyl)amino and Z is a halogen ion. Compounds of Formula I where X<SP>11</SP> is acetyl may be prepared from 5-[2-acetyl-5,5- dimethylcyclopent - 1 - en - 1 - yl] - 3 - methylpenta - 2,4 - dien - 1 - ol, in which the acetyl group is ketalized, for example with ethylene glycol, by brominating it and reacting the product with a triaryl or tri-(dialkylamino) phosphine, or by reacting the alcohol directly with triphenylphosphonium bromide in the presence of dimethylformamide. Compounds of Formula I in which X<SP>11</SP> is methyl or ethyl may be prepared by reacting the appropriate 4-(2- alkyl - 5,5 - dimethyl - cyclopent - 1 - en - 1 - yl)- but - 3 - en - 2 - one with acetylene to form a 5 - (2 - alkyl - 5,5 - dimethyl - cyclopent - 1 - en- 1 - yl) - 3 - hydroxy - 3 - methyl - penta - 4 - en- 1-yne, hydrogenating this product to form a 5- (2 - alkyl - 5,5 - dimethyl - cyclopent - 1 - en - 1- yl) - 3 - hydroxy - 3 - methyl - penta - 1,4 - diene, brominating this product with phosphorus tribromide to give a 5-(2-alkyl-5,5-dimethylcyclopent - 1 - en - 1 - yl) - 3 - methyl - penta- 2,4-dienyl bromide, and reacting this product with a triaryl or tri-(dialkylamino) phosphine.</p> |
