| 摘要 |
NEW MATERIAL:The compound of formula I [R<1> and R<2> are H or lower alkyl; R<3> is tri (lower alkyl) silyl or H; the group of formula II may be cyclized to form the group of formula III]. EXAMPLE:Ethyl 2-carboethoxy-5-hydroxy-5-trimethylsilylethynyl-1-cyclohexy- lideneacetate. USE:Synthetic intermediate of daunomycin, etc. PREPARATION:A compound of formula I whrerein R<1>-R<3> are H can be pre pared by reacting the compound of formula IV (R<1>' and R<2>' are lower alkyl) with the compound of formula CHidenticalC-R<3>, and hydrolyzing and/or desilylating the resultant compound of formula V. The product can be converted to another compound of formula I wherein the group of formula II is the group of formula III and R<3> is H by cyclization.
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