Valiolamines from valienamine

The first evidence for aminocarbapyranoses occurring in Nature dates back to early 70s with the discovery of validamine 202 (Chart 3), a carbasugar constituent of Validamycins, an antibiotic complex which shows growth inhibition activity against bacterial diseases of rice plants [50]. Shortly after, validamine 202, along with valiolamine 203 and valienamine 204, (Chart 3), were isolated from the fermentation broth of Streptomyces hygroscopicus var. limoneus [50],... 

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. ... 

A low yielding synthesis of 2-acetamido-5a-carba-2-deoxy-a-D,L-a//o- and gwlo-pyranose tetraacetates and some 3-acetamido-3-deoxy derivatives have been achieved starting from bicyclic acetate 87." By use of the same intermediate the preparations of valienamine and valiolamine have also been achieved." ... 

The mild conditions of the olefin metathesis reaction make it an ideal method for the preparation of cyditols and carbasugars [51, 52]. In general, the syntheses start from readily available carbohydrate derivatives that are converted to dienes and then submitted to RCM conditions. The resulting functionalized cyclohexenes are then converted to the target molecules in a few straightforward steps [53b]. According to this principle, the syntheses of (+)-cyclophellitol (230) (Scheme 1.40) [54], valienamine (233) (Scheme 1.41) [53, 55], valiolamine (236) (Scheme 1.42) [56], conduritol derivatives 238-240 (Scheme 1.43) [57], phosphatidyl inositol [58], and analogs (243) (Scheme 1.44) [59] have been reported. 

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