Functional group manoeuvring for tuning stability and reactivity: synthesis of cicerfuran, moracins (D, E, M) and chromene-fused benzofuran-based natural products

The protecting group manoeuvring as a strategy was applied for tuning the stability and reactivity of 4-(2,2-dibromovinyl)benzene-1,3-diol ( 12a ) and 6-(2,2-dibromovinyl)-2,2-dimethylchroman-7-ol ( 22 ) in the domino synthesis of benzofuran-based natural products ( 1-8 ). The functional group demands and their impact on the reactivity driven by electronic effects were successfully managed by varying the protecting groups with substituted gem -dibromovinylphenols in domino couplings and triarylbismuth reagents under palladium-catalyzed conditions. This approach paved the way for the synthesis of moracin M ( 1 ) and cicerfuran ( 2 ), and the first time synthesis of moracin D ( 3 ) and moracin E ( 4 ) along with chromene-fused benzofuran-based natural products ( 5-8 ) in overall good yields. The protecting group manoeuvring as a strategy was applied in tuning the stability and reactivity of substituted gem -dibromovinylphenols ( 12a and 22 ) for the domino synthesis of benzofuran-based natural products. ( 1-8 ).