TOTAL SYNTHESIS OF ACARBOSE AND ADIPOSIN-2

Article abstract of DOI:10.1016/0008-6215(89)84107-2

The first total synthesis is described of the α-D-glucosidase inhibitor acarbose (1a). 1,6-Anhydro-4'-O-(3,4-anhydro-6-deoxy-α-D-galactopyranosyl)-β-maltose (21), prepared from 1,6-β-maltotriose (3a), and (+)-4,7:5,6-di-O-isopropilydenevalienamine (28) gave two pseudo-tetrasaccharide derivatives separable as the per-O-acetyl derivatives (29 and 31) by chromatography, and their structures were established on the basis of 1H-n.m.r. spectroscopy.On acetolysis followed by acetylation, 29 afforded the peracetate (1b), which was O-deacetylated to give 1a.Likewise, adiposin-2 (2a), the 6''-hydroxy analogue of 1a, isolated from fermentation broth of Streptomyces calvus TM-521, was synthesised.