Syntheses of the potent inhibitors of neuraminidase, N-(1,2-dihydroxypropyl) derivatives of siastatin B and its 4-deoxy analogs.

Polyand multifunctional piperidines isolated from microorganisms and plants are powerful and specific glycosidase inhibitors, and they have the potential to produce a number of kinds of beneficial therapeutic effects such as antihyperglycemic, antiviral and anticancer activity, etc. l) A multifunctional piperidine, siastatin B (1) which was isolated as an inhibitor of neuraminidase by H. Umezawaet al.2) from a Streptomyces culture, resembles structurally sialic acid (JV-acetylneuraminic acid, 2). After achievement of the total synthesis3~5) and several totally-synthetic analogs,6-7* we have designed potential neuraminidase inhibitors,8'9) transition-state analogs and substrate analogs of neuraminic acid aided by molecular graphics tools. Here we wish to report the syntheses of the inhibitors,