Trehazolin synthesis trehazolamines

Feng, X., Duesler, E.N., and Mariano, P.S. (2005) Pyridinium salt photochemistry in a concise route for synthesis of the trehazolin aminocyclitol, trehazolamine. Journal of Organic Chemistry, 70 (14), 5618-5623. 

VII. Synthesis of Trehazolins 1. Trehazolins Having Trehazolamines at the Anomeric Center... 

Thus, the synthesis of trehazolin and its analogues required two precursors, the glycosyl isothiocyanate or amine analogues thereof, and trehazolamine or isothicya-nate analogues, respectively. 

Trehazolamine. Chiara has described a synthesis of trehazolamine, the aglycon of trehazolin, a powerful inhibitor of trehalase, wherein a pinacol cyclization provided the necessary cyclopentane framework (Eq. 3.2) [17]. Thus, treatment of the tetrabenzyl-protected keto aldehyde, derived from D-glucose, with Sml2 furnished the two cis diols exclusively as a 1 1 mixture of isomers in excellent yield (>90%) [18]. Previous studies of five-membered ring formation mediated by SmE have also reported good cis/trans selectivity, presumably due to the intervention of a samarium chelate. 

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