Gabosines

Gabosines which have been isolated from Streptomyces strains constitute a family of keto carbasugars, most of them possessing a trihydroxylated cyclohexenone structure. Because of their interesting bioactivities, a large number of synthetic approaches to these compounds have been proposed (for example [115, 116]). The shortest route (four to five steps) to gabosines I and G was accomplished starting... 

Scheme 29 Synthesis of (-)-gabosine I and gabosine G from D-glucono-1,5-lactone...

Son BW, Choi JS, Kim JC, Nam KW, Kim D-S, Chung HY, Kang JS, Choi HD (2002) Parasitenone, a New Epoxycyclohexenone Related to Gabosine from the Marine-Derived Fungus Aspergillus parasiticus. J Nat Prod 65 794... 

After this, an ever-increasing number of carbapyranoses from natural sources was discovered (e.g. validamine, acarbose, gabosines, etc.), whose interesting biological activities were soon ascertained. 

Gabosines represent a large group of secondary metabolites of great biological interest isolated from different Streptomycetes strains and traditionally they are referred to as ketocarbasugars due to the presence of a keto functionality on pyranose skeleton [42]. 

In a more recent synthesis, Lubineau and Billault [44] developed a novel method to access gabosine-related cyclohexene structures by exploiting a Nozaki-Kishi cyclization as the key step (Scheme 31). 

Bach, G. et al. Gabosines, New Carba-Sugars from Streptomyces. 3.3 1993 [42a]... 

Mehta G, Lakshminath S (2000) A norbornyl route to cyclohexitols stereoselective synthesis of conduritol-E, alio-inositol, MK 7607 and gabosines. Tetrahedron Lett 41 3509... 

Lubineau, A, Billault, I, New access to unsaturated keto carba sugars (gabosines) using an intramolecular Nozaki-Kishi reaction as the key step, J. Org. Chem., 63, 5668-5671, 1998. 

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