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Synthesis of Pyrano[3,2-c]pyrazol-7(1H)-one Derivatives by Tandem Cyclization of 2-Diazo-3,5-dioxo-6-ynoates (Ynones). | LitMetric

Synthesis of Pyrano[3,2-c]pyrazol-7(1H)-one Derivatives by Tandem Cyclization of 2-Diazo-3,5-dioxo-6-ynoates (Ynones).

Org Lett

Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) and Key Laboratory of the Assembly and Application of Organic Functional Molecules, Hunan Normal University, Changsha 410081, China.

Published: October 2015

The construct of the core of pyrano[3,2-c]pyrazol-7(1H)-one derivatives is realized. The key step includes a tandem cyclization, namely, a metal-free cascade 6-π electrocyclic ring closure-Michael reaction of 2-diazo-3,5-dioxo-6-ynoates (ynones). The cascade reaction cleanly generated the desired products in excellent yields under mild conditions.

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Source
http://dx.doi.org/10.1021/acs.orglett.5b02369DOI Listing

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