853193-61-0Relevant articles and documents
Solid-phase synthesis of [5.5]-spiroketals
Sommer, Stefan,Kuehn, Marc,Waldmann, Herbert
supporting information; experimental part, p. 1736 - 1750 (2009/08/14)
An efficient and reliable multi-step synthesis of 251 natural product-like [5.5]-spiroketals on solid supports has been developed. As central key step, a double intramolecular hetero-Michael (DIHMA) reaction to alkynones was applied. The sequence allows for introduction of numerous substituents on the scaffold and for variation of stereochemistry. [5.5]-Spiroketals bearing an additional ketone were obtained in high overall yields. Further diversification was achieved by reduction of the ketone and reductive amination using polymer-supported borohydride, Grignard reaction and conversion to oxime derivatives in the solution phase.
Stereoselective synthesis of the tetrahydropyran core of polycarvernoside A
Barry, Conor S.,Bushby, Nick,Harding, John R.,Willis, Christine L.
, p. 2683 - 2686 (2007/10/03)
(Chemical Equation Presented) A concise and stereoselective synthesis of the tetrasubstituted tetrahydropyran core of polycavernoside A was achieved in 55% overall yield from 3-benzyloxypropanal. A stereoselective allyl transfer reaction was used in the synthesis of enol ether 18 followed by a TFA-mediated cyclization to create the three new asymmetric centers in the tetrahydropyran with complete stereocontrol in a single-pot process.
