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A cinchona alkaloid-catalyzed domino Michael/hemiacetalization reaction of cyclic beta-oxo aldehydes and aromatic beta,gamma-unsaturated alpha-keto esters, resulting in the formation of spiro-dihydropyran architectures in good yield with high stereoselectivity (up to 97% ee), is presented.

3-Halopropenals 1 can behave as an alternative equivalent of beta-acylvinyl anions (I) in the presence of N-heterocyclic carbene precursor (IPr.HCl) and DBU to afford cyclic alpha,beta-unsaturated carbonyl derivatives, butenolides 4 and pyrazolone 6, after cyclization with 2 and 5, respectively.

Eine CuI‐katalysierte Mehrkomponentenreaktion verknüpft aromatische Alkine, p‐Toluolsulfonylazid und aromatische 2‐Oxobut‐3‐inoate zu den funktionalisierten 2‐Iminooxetanen I, die selektiv in zweierlei fünfgliedrige Stickstoffheterocyclen umgewandelt werden konnten (siehe Schema; Tf=Trifluormethansulfonyl; R=Et, iPr).

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