| 摘要 |
Cyclopentenones of the formula <FORM:1096427/C2/1> in which R1 denotes hydrogen or an alkyl radical and R2 denotes an alkyl, alkenyl, aryl, aralkyl or cycloalkyl radical, are prepared by (1) treating an hydroxycyclopentenone of the formula <FORM:1096427/C2/2> with a secondary amine of the formula ANHB, in which A and B denote organic radicals which, with the nitrogen atom, may form a heterocyclic group, (2) treating the resulting compound of the formula <FORM:1096427/C2/3> with a reagent capable of introducing the radical R2 to produce a tertiary alcohol of the formula <FORM:1096427/C2/4> and (3) dehydrating the tertiary alcohol. Reaction (i) is effected in known manner. Reaction (2) is effected with a Grignard or Reformatsky reagent or a metal alkyl, a number of suitable Grignard reagents being specified. Reaction (3) is effected in known manner, e.g. with sulphuric acid. The intermediates of the third formula above are new compounds and may be isolated. Examples describe (1) the treatment of 3-methyl-2-cyclopenten-2-ol-1-one with pyrrolidine to yield 1-N-pyrrolidino-3-methyl - 1(5) - cyclopenten - 2 - one, (2) the reaction of this compound with Grignard reagents prepared from magnesium and (a) 1-chloropentane, (b) n-butyl bromide, (c) benzyl chloride, (d) cyclohexyl bromide and (e) allyl chloride to yield, after the dehydration of the tertiary alcohol, products of the first formula above in which R2 is n-amyl, n-butyl, benzyl, cyclohexyl and allyl, respectively, and (3) the reaction of 3-methyl-2-cyclopenten-2-ol-1-one with di-n-propylamine or morpholine. Another specified secondary amine is piperidine. Both the new intermediates and the final products are useful in perfumery. |
