791839-26-4Relevant academic research and scientific papers
Stereoselective synthesis of the lituarine tricyclic spiroacetal
Robertson, Jeremy,Meo, Paul,Dallimore, Jonathan W. P.,Doyle, Bryan M.,Hoarau, Christophe
, p. 3861 - 3863 (2004)
(Chemical Equation Presented) Oxidative cyclizations of 2-(4-hydroxybutyl)furan derivatives provide spirobutenolide acetals directly; on the basis of this methodology, we describe an asymmetric synthesis of a tricyclic spirobutenolide precursor to the C(7
Asymmetric synthesis of the C(6-18) bis(tetrahydropyran)spiroacetal fragment of the lituarines
Robertson, Jeremy,North, Christopher,Sadig, Jessie E.R.
experimental part, p. 5011 - 5023 (2011/08/04)
We describe efforts to achieve a multigram synthesis of the tricyclic spiroacetal core of the lituarines based on the addition of acyl anion equivalent to 4-(2-furyl)butan-2-one (18). We report the first cases of chemoselective Achmatowicz reaction in the presence of a second furan ring that lacks an α-hydroxyl group. The use of lithiated methoxyallene provides an efficient one-step conversion of ketone 18 into a tricyclic Diels-Alder adduct (27). In the final route, asymmetric cyanosilylation of ketone 29 achieved the construction of the stereogenic C(12) 3°-alcohol centre. Subsequent butenylation, diastereoselective reduction of keto-alcohol (+)-33 and alkene cross metathesis set up an oxy-Michael reaction to close the C(8-12) tetrahydropyran ring. The second ring-closure, which completed the route, was achieved by oxidative spirocyclisation following our earlier work.
