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Carbanions of aryl 3-chloropropylsulfoxides have reacted with nonenolizable aldehydes to provide 2,3-disubstituted tetrahydrofurans. The diastereoselectivity is attributed to the cyclic transition state of the aldol addition and has increased when the aromatic ring of the sulfoxide contains electron-withdrawing subsituents, whereas that of the aldehyde has electron-donating groups.

1,2-Metallate rearrangements involving reaction of 1-metallated glycals with organolithium reagents under copper(I) me-diation give alkenylpolyol chains in 45-91% yield (19 examples). The reaction was applied to a formal synthesis of KRN7000 as well as a synthesis of a δ5,6-ceramide derivative. [ABSTRACT FROM AUTHOR]

The synthesis ofthe novel 2′,3′-cyclopropane nucleoside3′-deoxy-3′-C-hydroxymethyl-2′,3′-methylene-uridineis described. Stereoselective construction of the cyclopropane ringwas achieved via Simmons–Smith cyclopropanation of a benzylprotected silyl enol ether, which was itself derived from 1,2-O-isopropylidene-α-d-xylofuranose. [ABSTRACT FROM AUTHOR]

A highly enantioselective, organocatalytic, and scalable synthesis of a very unusual cis-decalin-cis-hydrindane tricyclic diterpenoid system has been achieved. Despite the prevalent pharmacological space that the related trans,trans and trans,cis-systems occupy, there have been no reports of an asymmetric synthesis of the cis,cis systems in the literature until now. We demonstrate the flexibility of our approach not only through access to a diverse range of products, all of which are attained in exceptionally high selectivities, but also by showing their easy conversion to the corresponding trans,cis-system and other derivatives., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)