[Show abstract][Hide abstract] ABSTRACT: An efficient intramolecular Diels-Alder (IMDA) strategy for the construction of the [5-7-6] tricyclic core (18) of guanacastepenes has been developed from cis- and trans-1,3-butadiene-tethered 4-oxopent-2-ynoic acid ethyl esters 10 and 11. This method facilitates the synthesis of C8-epi-guanacastepene O (36) in a very efficient manner.
The Journal of Organic Chemistry 10/2006; 71(18):6892-7. DOI:10.1021/jo060996h · 4.64 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Construction of the [5-7-6] tricyclic core of guanacastepenes was attempted by using the intramolecular Diels-Alder (IMDA) reaction and Me(3)Al-mediated ring opening of the oxabridge as key synthetic steps. The illustrated chemistry demonstrated a synthetic feasibility to build up the framework of guanacastepenes by the IMDA reaction. [reaction: see text]