Valiolamines synthesis

Horii and Fukase first succeeded in synthesis of (+)-valiolamine (205) by stereoselective chemical conversion of(+)-203 through the key intermediate... 

In order to develop potent D-glucosidase inhibitors, a synthesis of carba-disaccharides containing valiolamine (205) was attempted by Horii and his coworkers utilizing method c. Coupling 205 with the 4-ketose 403, using NaBHjCN and hydrochloric acid, was effective in DMF, giving, after deprotection, the epimeric carba-disaccharides (404 and 405). The saturated... 

Lemaire et al. have developed a efficient fructose-1,6-bisphosphate aldolase (FBPA)-mediated synthesis of aminocyclitol analogs of valiolamine [34], This one-pot route involves the formation of two C—C bonds where four stereocenters are created. The first C—C bond formation reaction is catalyzed by the aldolase, coupling DHAP to nitrobutyraldehydes the other one is the result of a highly stereoselective intramolecular Henry reaction occurring on the intermediate nitroketone under acidic conditions during the aldolase-catalyzed reaction and phytase-catalyzed phosphate hydrolysis coupled step (Scheme 4.13). 

Scheme 4.13 Multi-enzyme route for the synthesis of aminocyclitol analogs of valiolamine...

Another unexpected rearrangement was encountered in the synthesis of 1 - e/u -valiolamine, when the alkene 4 was subjected to dihydroxylation conditions. Thus, heating of a mixture of 4 with a catalytic amount of OSO4 in a water/pyridine/t-butanol mixture containing trimethylamine N-oxide under reflux for 2 days gave a mixture of 5 (29%) and the a-diol 6 (14%) together with 46% of unchanged alkene 4. 

The majority of naturally occurring aminocarbasugars bears the amino functionality located at the pseudoanomeric position however, replacement of one or more hydroxyl groups by amino functions on the carbasugar backbone may offer great opportunities for structural and stereochemical variation. This section is subdivided into three subsections, dealing with the synthesis of validamine, valiolamine, and valienamine-type carbaglycosyl amine structures. 

Fukase, H. et al. Synthesis of a Branched-Chain Inosose Derivative, a Versatile Synthon ofN-Substituted Valiolamine Derivatives from D-Glucose. 3.4.2 1992 [58a]... 

Ogawa S, Tsunoda H (1992) Pseudo-sugars. XXXI. New synthesis of 2-amino-5a-carba-2-deoxy-a-DL-glucopyranose and its transformation into valien-amine and valiolamine analogues. Liebigs Ann Chem 6 637-641... 

Opening a new route to valiolamine analogs, this work broadens the scope of the enzymatic aldol reaction combining in one pot the formation of two carbon-carbon bonds with high stereoselectivity. We demonstrate a short efficient synthesis of new nitro- and aminocychtols that considerably reduces the laborious... 

Fukase, H., and Horii, S., Synthesis of valiolamine and its A-substituted derivatives AO-128, validox-ylamine G, and validamycin G via branched-chain inosose derivatives, J. Org. Chem., 57, 3651, 1992. Morgan, B.P., Holland, D.R., Matthews, B.W., and Bartlett, P.A., Structure-based design of an inhibitor of the zinc peptidase thermolysin, J. Am. Chem. Soc., 116, 3251, 1994. 

J. Horii, H. Fukase, T. Matsuo, Y. Kameda, N. Asano, and K. Matsui, Synthesis and a-D-glucosidase inhibitory activity of substituted valiolamine derivatives as potential oral antidiabetic agents, J. Med. Chem., 29 (1986) 1038-1046. 

T. K. M. Shing and L. H. Wan, Facile synthesis of valiolamine and its diastereomers from (-)-quinic acid. Nucleophilic substitution reactions of 5-hydroxymethyl-cyclohexane-l,2,3,4,5-pentol, J. Org. Chem., 61 (1996) 8468-8479. 

O. Sellier, P. vande Weghe, D. LeNouen, C. Strehler, and J. Eustache, Ring closing metathesis as an efficient approach to branched cyclitols and aminocyclitols A short synthesis of valiolamine, Tetrahedron Lett, 40 (1999) 853-856. 

H. Fukase and S. Horii, Synthesis of a branched-chain inosose derivative. A versatile synthon of JV-substituted valiolamine derivatives from D-glucose, J. Org. Chem., 57 (1992) 3642-3650 3651-3658. 

Horii, S., Fukase, H., Matsuo, T., Kameda, Y., Asano, N., and Malsui, K. 1986. Synthesis and. alpha.-D-glucosidase inhibitory activity of N-substituted valiolamine derivatives as potential oral antidiabetic agents. Journal of Medicinal Chemistry, 29(6), 1038-1046. 

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." ... 

Shing and Wan have employed quinic acid as starting material for a synthesis of valiolamine 47 and several analogues, 48-50, of this aminocyclitol analogue. 

L. El Blidi, M. Ahbala, 1. Bolte, M. Lemaire, Straightforward chemo-enzymatic synthesis of new aminocyclitols, analogues of valiolamine and their evaluation as glycosidase inhibitors. Tetrahedron Asymmetry 17 (2006) 2684-2688. 

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