Discodermolide is a marine natural product reported to inhibit the proliferation of T cells and exhibit immunosuppresive activity. Total syntheses of the natural antipode of discodermolide and several variants are reported. These studies provide reagents to investigate discodermolide's recently discovered ability to bind and stabilize microtubules in cells. Retrosynthetically, the polypropionate is divided into three fragments of approximately equal complexity. This modular strategy provides convergency in the synthesis and facilitates the preparation of discodermolide-based reagents.

Syntheses of discodermolides useful for investigating microtubule binding and stabilization

Liphagal, a Selective Inhibitor of PI3 Kinase α Isolated from the Sponge Aka coralliphaga: Structure Elucidation and Biomimetic Synthesis

The addition of aldehydes and ketones to alkenes in the presence of Bronsted acids is usually called the Prins reaction.1,2 Addition of the protonated carbonyl compound to the alkene gives a β-hydroxy carbocation which reacts with a nucleophile such as chloride, water or acetate to give (1), adds to a second molecule of aldehyde to give (2) or loses a proton to give homoallylic alcohol (3; Scheme 1). Formaldehyde and electron-deficient carbonyl compounds undergo concerted thermal ene reactions with alkenes at temperatures ranging from 100 to 200 °C to give homoallylic alcohols (equation 1; R1 = H, CCl3, or CO2R).3–7 A wide variety of carbonyl compounds undergo Lewis acid catalyzed reactions with alkenes to give homoallylic alcohol ene adducts in excellent yield with high selectivity, although in some cases γ-chloro alcohols are formed as by-products.8,9 Recent investigations suggest that at least some of these Lewis acid catalyzed ene reactions are stepwise, rather than concerted, but that the intermediate bears more resemblance to a π-complex than to the open carbocation intermediate in the Prins reaction.

The Prins and Carbonyl Ene Reactions

Methods for the construction of trans-hydrindane rings and their origins in steroid chemistry. Vitamin D total synthesis

Second generation of steroid synthesis via o-quinodimethane

La synthese de la bruceantine(−) pourrait s'effectuer a partir d'un acide oxo-3 perhydronaphtoique

Acyclic diastereoselection as a synthetic route to quassinoids: a Claisen rearrangement based strategy for bruceantin

La stereochimie C 8 -C 14 du steroide est etablie, par une transposition de Cope permettant la formation stereocontrolee des noyaux C et D par cyclisations en milieu acide. La formation d'un groupe hydroxy-11β permet l'introduction stereocontrolee du methyl 19 en protegeant la fonction cetone en -3 par un acetal

Synthesis of (.+-.)-11-ketoprogesterone, a precursor to the corticosteroids. An improved method for the introduction of the carbon 19 methyl group into A-ring aromatic steroids

Tein Fu Wang

Papers

Acyclic diastereoselection as a synthetic route to quassinoids: a Claisen rearrangement based strategy for bruceantin

Synthesis of (.+-.)-11-ketoprogesterone, a precursor to the corticosteroids. An improved method for the introduction of the carbon 19 methyl group into A-ring aromatic steroids

Practical routes to two functionalized decalones for the synthesis of quassinoids

Practical Routes to Two Functionalized Decalones for the Synthesis of Quassinoids.

Acyclic diastereoselection as a synthetic route to quassinoids: a claisen rearrangement based strategy for bruceantin