Analogues de la lincomycine. I. Allongement de la chaîne du di-O-isopropylidène-1,2:3,4-α-D-galacto-hexodialdopyrannose-1,5

Lincomycin analogues. I. Chain-extensions of 1,2:3,4]-di-O-isopropylidene-α-D -galacto-hexodialdo-1,5-pyranose The title aldehydosugar 1 treated with Wittig reagents led in good to excellent yields to the unsaturated sugar derivatives 3–7 and 10–15, 8 having been prepared by condensation of 1 with malonic acid. The configuration (Z or E) of each compound obtained has been established by ¹H-NMR. These chain-extensions constitute the first synthetic step towards the preparation of lincomycin analogues.