Facile one-pot synthesis and in silico study of new heterocyclic scaffolds with 4-pyridyl moiety: Mechanistic insights and X-ray crystallographic elucidation.

4-Acetylpyridine and malononitrile were allowed to react in a 3MCRs with dimedone or cyclohexa-1,3-dione under reflux to afford 4-methyl-4-(pyridin-4-yl)-5,6,7,8-tetrahydro-4-chromene derivatives respectively. The mechanism of the reaction has been studied and the structures elucidated by analytical, spectral as well as X-ray crystallographic data. Heterocyclic compounds find widespread application in pharmaceutical and agrochemical products.

(2,4,5)-5-Meth-oxy-4-methyl-3-oxohept-6-en-2-yl benzoate.

The title compound, CHO, was synthesized in the course of the total synthesis of fusaequisin A in order to verify and confirm the configurations of the stereogenic centers and to exclude the possibility of epimerization during the methyl-ation process. The crystal structure of the title compound at 100 K has ortho-rhom-bic (222) symmetry. The absolute configuration was determined by anomalous dispersion and agrees with the configuration of the allylic alcohol used in the synthesis.

Photochemical Approach to the Cyclohepta[b]indole Scaffold by Annulative Two-Carbon Ring-Expansion.

We report on the implementation of the concept of a photochemically elicited two-carbon homologation of a π-donor-π-acceptor substituted chromophore by triple-bond insertion. Implementing a phenyl connector between the slide-in module and the chromophore enabled the synthesis of cylohepta[b]indole-type building blocks by a metal-free annulative one-pot two-carbon ring expansion of the five-membered chromophore. Post-irradiative structural elaboration provided founding members of the indolo[2,3-d]tropone family of compounds.