An Efficient One Pot Synthesis of 2,3-Diphenyl-4(H)Oxofuro(3,2-c) (1)Benzopyrans

Furo[3,2-c]coumarins carrying carbon substituents at C-2 and/or C-3. Isolation, biological activity, synthesis and reaction mechanisms

“…On the other hand, the synthesis of some analogs of coumestrol has been achieved by acid or base catalyzed condensation of 4hydroxycoumarin with benzoin, acting as a surrogate of an ahalocarbonyl compound. 134 The proposed raction mechanism was quite similar to that of the Feist-Bénary reaction. The reaction proceeds in good to excellent yields and accepts a wide variety of substituents on the R side.…”

First Synthesis of Furo[3,4‐c]coumarins.

“…Among furocoumarins if one restricts the fusion of furan ring with the lactone ring of coumarin, three structural isomers; furo[2,3-c] (I), furo[3,2-c] (II) and furo [3,4-c] (III) are possible ( Figure 1). In literature a large number of reports are documented for the synthesis of furo[2,3-c] and furo [3,2-c] coumarins [12][13][14][15][16][17][18][19][20], however the synthesis of furo [3,4-c]coumarin to our knowledge has not been reported except for a single report on a saturated skeletal analog of furo [3,4-c]coumarin [21]. Hence in continuation of our interest in heterocyclic fused coumarins [20,[22][23][24] it was thought worthwhile to envisage a synthetic route to such novel molecules.…”

A Pd-Catalyzed Heteroannulation Approach to 2,3-Disubstituted Furo[3,2-c]coumarins

“…Under these conditions, 4a was obtained in a satisfactory 64% yield within 2 h reaction time. Furo[3,2- c ]coumarins as well as the structurally related dihydrofurocoumarins and coumestans are valuable compounds endowed with many interesting biologically properties. , We therefore sought to investigate the unexpected behavior of alkynyl coumarins in this cyclization process more deeply.…”