| 摘要 |
NEW MATERIAL:Title compounds of formula I or II (R<1> is H, lower alkyl, cycloalkyl; R<2> is alkyl cycloalkyl; n is 0, 1-2; dotted lines show positions where double bonds may exist so as to satisfy the valency of carbonas. EXAMPLE:Ethyl 2,5,7-trimethyl-4,7-cotadienoate of formula III. USE:Base of cosmetics, perfumes, intermidiates for food and tobacco flavor and for medicines and agricultural chemicals. They are analogs of farnesylacetic esters which have physiological activity against ulcer formation. PREPARATION:The reaction between an allyl alcohol given as formula IV and an orthocarboxyic ester of formula V (R<3-5> are lower alkyl) in the presence of an organic acidic catalyst gives a gamma,delta-unsaturated ester of formula VI (R<6> is R<3> or R<4> or R<5>), which is, when necessary, converted to the objective compound of formula I by a conventional method. |
