.alpha.-neuraminic acid, n-acetyl-2-o-(7,26-dioxo-10,13,16,19,22-pentaoxa-6,25-diazapentaconta-35,37-diyn-1-yl)-
.alpha.-neuraminic acid, n-acetyl-2-o-(7,26-dioxo-10,13,16,19,22-pentaoxa-6,25-diazapentaconta-35,37-diyn-1-yl)-