Synthesis of macrocyclic trienes and intramolecular Diels-Alder trienes, containing the ester on the dienophilic unit, was studied. (E,E)-diene 5b could be prepared in high 89% yield from (E)-vinylstannane TBDPS ether 3b and (E)-vinyl iodide 4b by car...
Synthesis of macrocyclic trienes and intramolecular Diels-Alder trienes, containing the ester on the dienophilic unit, was studied. (E,E)-diene 5b could be prepared in high 89% yield from (E)-vinylstannane TBDPS ether 3b and (E)-vinyl iodide 4b by carrying out Stille coupling employing Pd(CH_3CN)_2Cl_2 as a catalyst and Hu¨nig base as an additive in a 1:1 ixture of THF and DMF. The target macrocyclic triene 10a, a precursor to trannsannular Diels-Alder reaction, could be obtained from 5b through a three-step sequence of reaction: desilylation, esterification with maleic anhydride and lactonization by the Mitsunobu method. Intramolecular Diels-Alder trienes 8c, 8d, 8f were also obtained from E,E-diene 5d.