Stereoselective Synthesis of 2,8-Dioxabicyclo[3.3.1]nonane Derivatives via a Sequential Michael Addition/Bicyclization Reaction

Abstract

A highly efficient and stereoselective synthesis of coumarin-, 1,3-cyclohexanedione-, and 1,4-naphthoquinone-fused 2,8-dioxabicyclo[3.3.1]nonanes is described. This was achieved via a sequential Michael addition/bicyclization reaction from easily accessible 3-(2-hydroxyphenyl)-1-phenylprop-2-en-1-one derivatives. Three chemical bonds (one C-C bond and two C-O bonds), two six-membered cycles, and two stereogenic centers were formed in a one-pot operation.

Selective Synthesis of New Tetracyclic Coumarin‐fused Pyrazolo[3,4‐b]pyridines and Pyrazolo[3,4‐b]pyridin‐6(7H)‐ones

“…However, the aliphatic aldehydes show the poor yields of the expected products. In continuation with our previous work in minimizing the efforts in construction of coumarin‐fused heterocyclic frameworks, we herein report a solvent‐tunable selective synthesis of new tetracyclic system by the three‐component reactions of 4‐hydroxycoumarin ( 1 ), aldehydes ( 2 ), and 5‐aminopyrazoles ( 3 ). Coumarin‐fused 4,7‐dihydro‐1H‐pyrazolo[3,4‐ b ]pyridines were obtained in refluxing acetonitrile in the presence of acetic acid.…”

Coumarin heterocyclic derivatives: chemical synthesis and biological activity

“…207 When the 2- phenylchroman-4-ol partner 285 is replaced by cinnamaldehyde derivatives 287, the modied reaction evolves through a Michael addition/bicyclization sequence leading to coumarin-fused 2,8-dioxabicyclo[3.3.1]nonane 288 (Scheme 90). 208 A one-pot protocol provided an efficient entry to 9,10-dihydro-6H-chromeno [4,3-d]imidazo[1,2-a]pyridin-6-one derivatives 290 (Scheme 91). 209 The authors proposed the Et 3 N-catalyzed mechanism shown in Scheme 91.…”

Stereoselective Construction of 2,8‐Dioxabicyclo[3.3.1]nonane/nonene Systems from 3‐C‐Branched Glycals

“…Recently, synthesis of aryl‐ring‐fused 2,8‐dioxabicyclo[3.3.1]nonane systems has been reported by using the Pd II ‐catalyzed cascade reaction through (2‐hydroxyphenyl)boronic acid8 or AgOTf‐catalyzed domino reaction of phenols/naphthols,9 with a series of 2‐hydroxychalcone derivatives. A catalyst‐free10 or iodine‐catalyzed11 Michael condensation of 2‐hydroxychalcones with the activated methylene groups followed by bicyclization reaction to provide 2,8‐dioxabicyclo[3.3.1]nonane derivatives has also recently been reported. However, all the above methods have been directed to the synthesis of mono‐ or bi‐aryl fused 2,8‐dioxabicyclo[3.3.1]nonane systems involving 2‐hydroxy chalcone derivatives as one of the common precursors.…”