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Robinson annulation

9 real reactions from the literature, on six-membered cyclic ketones, enamines, α,β-unsaturated ketones and 1,3-diketones. Each scheme shows starting materials, conditions and products, with the yield and reference where the source reports them.

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  1. Robinson annulation: 4-(cyclohexen-1-yl)morpholine (an enamine) with dioxane, Δ gives 4,4a,5,6,7,8-hexahydro-2(3H)-naphthalenone (the annulated cyclohexenone).
    Robinson annulationOrg. Synth. Coll. Vol. 5, p. 869

  2. Robinson annulation: 2-methylcyclohexanone (a six-membered cyclic ketone) and 3-(triethylsilyl)but-3-en-2-one (an α,β-unsaturated ketone) with KOtBu / tBuOH gives the annulated cyclohexenone.
    Robinson annulationJ. Am. Chem. Soc. 1973, 95, 6152

  3. Robinson annulation: 2-methylcyclohexanone (a six-membered cyclic ketone) with 1) NaH, 48 h / RT; 2) then add but-3-yn-2-one gives 4a-methyl-5,6,7,8-tetrahydronaphthalen-2(4aH)-one (the annulated cyclohexenone).
    Robinson annulationJ. Am. Chem. Soc. 1950, 72, 494

  4. Robinson annulation: methyl 3-oxo-4-pentenoate (an α,β-unsaturated ketone) and 5-methoxy-1-methyl-2-tetralone (an aryl alkyl ether) with NaOMe; MeOH gives the annulated cyclohexenone. 32% yield.
    Robinson annulationTetrahedron 1968, 24, 3095

  5. Robinson annulation: 5-methoxy-1-methyl-2-tetralone (a six-membered cyclic ketone) and 1-chloro-3-pentanone (a primary alkyl chloride) with TsOH; PhMe gives the annulated cyclohexenone. 58% yield.
    Robinson annulationSynth. Commun. 1999, 29, 249

  6. Robinson annulation: 5-methoxy-2-tetralone (a six-membered cyclic ketone) with 1) nBuLi; 2) add; 3) acidic workup gives the annulated cyclohexenone. 42% yield.
    Robinson annulationThiemann, Thies dissertation

  7. Robinson annulation: a six-membered cyclic ketone and 4-chloro-2-butanone (a primary alkyl chloride) with TsOH; PhMe gives the annulated cyclohexenone. 30% yield.
    Robinson annulationJ. Am. Chem. Soc. 1994, 116, 2665

  8. Robinson annulation: a six-membered cyclic ketone and 1-penten-3-one (an α,β-unsaturated ketone) with NaOMe, MeOH / PhH gives the annulated cyclohexenone.
    Robinson annulationTetrahedron Lett. 1993, 34, 339

  9. Robinson annulation: 2-methyl-1,3-cyclohexanedione (a 1,3-diketone) and methyl vinyl ketone (an α,β-unsaturated ketone) with 1) KOH, CH3OH, Δ; Δ gives (+-)-Wieland-Miescher ketone (the annulated cyclohexenone).
    Robinson annulationOrg. Synth. Coll. Vol. 5, p. 486