Synthesis of tricolorin F.

A hetero-trisaccharide resin glycoside of jalapinolic acid known as tricolorin F has been synthesized. The approach involved the preparation of intermediate 5 and a subsequent coupling reaction with imidate 6 to produce disaccharide 7, which after deacetylation generated intermediate 8. A further coupling between this glycosyl acceptor and the quinovose glycosyl donor 9 resulted in the formation of the tricoloric acid C derivative 10. Basic hydrolysis afforded the intermediate 11, which was subsequently lactonized under Yamaguchi conditions to produce protected macrolactone 12. Removal of acetonide and benzyl protecting groups afforded pure tricolorin F (1).