604775-07-7Relevant articles and documents
Stereoselective synthesis of spirocyclic oxindoles via prins cyclizations
Paola Castaldi,Troast, Dawn M.,Porco Jr., John A.
supporting information; experimental part, p. 3362 - 3365 (2009/12/01)
The synthesis of spirocyclic oxindole pyran and oxepene frameworks using highly stereoselective Prins cyclizations of homoallylic and bishomoallylic alcohols and isatin ketals is described.
Establishing the absolute configuration of the asbestinins: Enantioselective total synthesis of 11-acetoxy-4-deoxyasbestinin D
Crimmins, Michael T.,Ellis, J. Michael
, p. 17200 - 17201 (2007/10/03)
A highly stereoselective synthesis of 11-acetoxy-4-deoxyasbestinin D (1) has been completed in 26 linear steps. The synthesis hinges on a selective glycolate aldol addition to establish the C-2 stereocenter, a ring-closing metathesis reaction to complete the oxonene, and an intramolecular Diels-Alder cycloaddition to establish the relative configuration at C-1, C-10, and C-14. This initial total synthesis of an asbestinin also serves to confirm the absolute configuration of this subclass of the C-2-C-11-cyclized cembranoid natural products. Copyright
A Second-Generation Synthesis of the C1-C28 Portion of the Altohyrtins (Spongistatins)
Hubbs, Jed L.,Heathcock, Clayton H.
, p. 12836 - 12843 (2007/10/03)
A practical second-generation synthesis of an advanced intermediate in our total synthesis of altohyrtin C (spongistatin 2) has been developed. A new approach to the C1-C15 (AB) portion features a vinyllithium addition to an aldehyde followed by a palladium-catalyzed allylic reduction to install the troublesome C13-C15 segment. Our general approach to the C16-C28 (CD) spiroketal has been retained, but some improvements have been made. Most notably, the kinetically controlled CD-spiroketalization reaction now proceeds in high yield with excellent diastereoselection. This new strategy uses the anti-aldol coupling used in our first-generation synthesis to join AB and CD fragments. A total of 9.6 g of intermediate 57 has been produced using this improved route.