A simple l-proline-catalysed regio- and diastereoselective synthesis of spiro[pyrido[2,3-d]pyrimidin-2-amine-6,5′-pyrimidines] in water through a strategy of one-pot multicomponent domino reaction of 2,6-diaminopyrimidin-4-one, aldehydes and barbituric acids is described. The notable advantages of the protocol are operational simplicity, mild reaction conditions, simple purification process involving no chromatographic techniques, wide substrate scope, and high yields. The method delivers the desired product within short reaction time and with a diastereoselectivity of 61:39 to 100:0, which makes the protocol highly attractive.

A variety of sugar-fused chromanono pyrrolidines/pyrrolizidines/thiolizidines have been synthesized by intermolecular 1,3-dipolar cycloaddition reaction of azomethine ylides (generated from glucose aldehyde and different secondary amino acids) with various 3-arylidene chroman-4-ones as dipolarophiles. The solvent effect on the 1,3-dipolar cycloaddition reaction is also studied.

Correction to: Iodobenzene-Promoted Pd-Catalysed ortho-Directed C–H Activation: The Synthesis of Benzothiazoles via Intramolecular CouplingSynOpen 2017; 01(01): 0001-0007DOI: 10.1055/s-0036-1590200

We describe herein an efficient synthesis of the C1–C9, C11–C19 pyran moiety and C18–C24 core fragments of macrolactin 3. The prominent features of this work include construction of the Z-double bond of the 1,3-(Z,E)-diene system utilizing Horner–Wadsworth–Emmons­ reaction under Still–Gennari conditions. A Sharpless asymmetric epoxidation and subsequent epoxide opening under BF3·OEt2 conditions were applied to generate the stereogenic centers at C15 and C16, oxa-Michael addition and Jacobsen resolution facilitate the synthesis of the fragments.