Formal Synthesis of 3-Deoxy-d-manno-Octulosonic Acid (KDO) and 3-Deoxy-d-arabino-2-heptulosonic Acid (DAH)

Practical synthetic routes to 3-deoxy- d -manno-octulo­sonic acid (KDO) and 3-deoxy- d -arabino-2-heptulosonic acid (DAH) from common sugar substrates are reported. Chain homologation of the sugar substrates was accomplished by Wittig olefination and Corey–Fuchs alkynylation. A new cyclization strategy was investigated to access the desired pyranosyl isomer of the KDO target.