Design, Synthesis, and Biological Investigation of Thailanstatin A and Spliceostatin D Analogues Containing Tetrahydropyran, Tetrahydrooxazine, and Fluorinated Structural Motifs.

Thailanstatin A and spliceostatin D, two naturally occurring molecules endowed with potent antitumor activities by virtue of their ability to bind and inhibit the function of the spliceosome, and their natural siblings and designed analogues, constitute an appealing family of compounds for further evaluation and optimization as potential drug candidates for cancer therapies. In this article, the design, synthesis, and biological investigation of a number of novel thailanstatin A analogues, including some accommodating 1,1-difluorocyclopropyl and tetrahydrooxazine structural motifs within their structures, are described. Important findings from these studies paving the way for further investigations include the identification of several highly potent compounds for advancement as payloads for antibody-drug conjugates (ADCs) as potential targeted cancer therapies and/or small molecule drugs, either alone or in combination with other anticancer agents.

Synthesis of dibenzo[a,d]cycloheptanoids via aryne insertion into 2-arylidene-1,3-indandiones.

A novel and unexpected aryne insertion cascade reaction on 2-arylidene-1,3-indandiones via conjugate addition of fluoride followed by formal C-C insertion is developed to afford dibenzo[a,d]cycloheptanoid derivatives in good yields with a single isomer. This reaction represents a rare instance of cyclic enone C-C bond insertion (acyl-alkenylation) in aryne chemistry. Interestingly, 2-arylidene-1,3-indandiones bearing electron rich functional groups provided dibenz[a,c]anthracene-9,14-dione derivatives via [4 + 2] cycloaddition followed by ring expansion.