Coupling of Key Intermediates 147 and

EtjSiOTf (15 equlv.), 2,6-lutldlne (20 equlv.), CH2CI2,0 °C then silica gel, CH2CI2, 25 °C (94%) 

It was anticipated that fragments 147 and 214 could be united through an amide bond linking the nitrogen atom of the latter with C-8 of the former. Indeed, the active ester formed by treatment of carboxylic acid 147 with 1,3-diisopropylcarbodiimide and 1-hydro-xybenzotriazole reacts efficiently with amine 214 to afford dihydroxy amide 215 in 95 % yield. This convergent union creates a molecule that possesses all but two carbon atoms of the natural product. 

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