Validamines preparation

Validamine (202) and (+)-valienamine ° (203) have been synthesized as the penta-V,0-acetates from the optically active dibromide (51), following essentially the procedure described for the preparation of their racemic modifications. 

Total syntheses of (+)-validamycin B (compoimd 367) [199,200], ( + )-valida-mycin A(365) [201,202], validoxylamine B (362) [200], (+)-validoxylamine A(361) and (+)-validamycin E (compoimd 368) [202] have also been reported by the same group. In another report, cleavage of the imino bonds of validoxylamine A derivatives with A-bromosuccinimide was demonstrated. This method reports the preparation of synthetically useful derivatives of (+)-validamine and valienamine [203]. 

Valiolamine and its C-1 and C-2 epimers, together with other analogues, have been prepared from (-)-quinic acid and racemic validamine, together with its C-1 and C-2 isomers, have been synthesized from (phenylsulfonyl)-7-oxa-bi-cyclo[2.2.1]heptane derivatives. Six A-alkyl derivatives of P-valienamine have been made and shown to be potent and specific inhibitors of P-glucocerebrosi-dase the best was the -octyl derivative. ... 

The 5-C-nitromethyl sugars mentioned above, obtained from D-glucose, have also been used to prepare validamine (38) and 5-epi-validamine (39), by use of a Michael addition of ammonia to the nitrocyclohexene intermediates (40) a related sequence yielded... 

A synthesis has been reported of (-t-) fortamine hrom die known conduritol derivative 88. The preparation from the known ketolactone 89 of carba-a and - -D-glucopyranose as well as validamine, in which the key step is a stereoselective addition of nitromethane tt> the keto... 

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