Enantiospecific Approach toward Pentalenolactone

Formal Synthesis of (±)-Pentalenolactone A Methyl Ester

We report the formal synthesis of (±)-pentalenolactone A methyl ester from simple 2-methoxyphenol. The key features of our route are as follows: a Diels-Alder reaction of masked o-benzoquinone to assemble the functionalized bicyclo[2.2.2]octenone, a continuous-flow oxa-di-π-methane rearrangement for building the diquinane core (AB ring), and an oxidative cleavage/oxidation sequence for annulation of the δ-lactone (C ring).

Iodine-Catalyzed Iso-Nazarov Cyclization of Conjugated Dienals for the Synthesis of 2-Cyclopentenones

Molecular iodine was identified as an efficient catalyst for the cycloisomerization of conjugated dienals to substituted 2-cyclopentenones. DFT calculations suggested an unexpected concerted character for this cyclization.

A Survey of Recent Synthetic Applications of 2,3-Dideoxy-Hex-2-enopyranosides

Unsaturated carbohydrate derivatives are useful intermediates in synthetic transformations leading to a variety of compounds. The aim of this review is to highlight the rich chemistry of ∆-2,3 unsaturated pyranosides, emphasizing the variety of transformations that have been carried out in these substrates during the last decade.

End-group differentiating ozonolysis of furocoumarins

Ozonolysis of furocoumarins followed by reductive work-up yields not only common symmetrical dialdehydes, but also o-formylumbelliferones with moderate-to-high yields.