Total synthesis of soraphen A(1 alpha)

The convergent synthesis of macrolide soraphen A(1 alpha) is described star ting from glucose (western part) and mannose (eastern part). Mannose was co nverted into a 2-deoxyribohexopyranoside that could be methylated and reduc ed stereoselectively. Chain elongation at Cd was carried out by stereoselec tive addition of a magnesium acetylide. The two fragments (western and east ern) were assembled by a Julia olefination followed by macrolactonization. The introduction of the methyl group at C-2 of norsoraphen occurred stereos electively for thermodynamic reasons.