Synthesis of 4,6:2′,3′:4′,6′-tri-O-cyclohexylidene-α,α′-trehalose 2-palmitate: an intermediate for the synthesis of mycobacterial 2,3

Add time:09/25/2019    Source:sciencedirect.com

The aim was to `triprotect' trehalose by placing various acetals, or related protecting groups, across the 4,6-, 2′,3′-, and 4′,6′-positions, leaving the 2,3-positions free for subsequent acylation. Isopropylidene and ethylidene acetals were studied, with the formation of a small amount of 4,6:2′,3′:4′,6′-tri-O-isopropylidene- α,α′-trehalose. 4,6:4′,6′-Di-O-benzylidene-2′,3′-O-(tetraphenyldisiloxane-1,3-diyl)-α,α′- trehalose 2,3-diacetate was prepared in low yield. 1,1-Dimethoxycyclohexane reacted with methyl α-d-glucopyranoside to afford the 4,6-O-cyclohexylidene derivative, isolated as the diacetate; mild acid cleavage of the acetal gave the 2,3-diacetate. 4,6:2′,3′:4′,6′-Tri-O-cyclohexylidene-α,α′-trehalose is the major product of the reaction between α,α′-trehalose and 1,1-dimethoxycyclohexane. 2,3:4,6:2′,3′:4′,6′-Tetra-O- cyclohexylidene-, 4,6:4′,6′-di-O-cyclohexylidene-, and 4,6-O-cyclohexylidene-α,α′-trehaloses were also isolated in lower yields, all acetals being characterised as their peracetates. The proportions of the different trehalose acetals were dependent upon the molar ratio of 1,1-dimethoxycyclohexane and particularly on the reaction temperature. The triprotected trehalose acetal was acylated with palmitic acid, with excellent regioselectivity, affording the 2-O-palmitoyl ester. This 2-monoacylated, triprotected trehalose is a key intermediate for the synthesis of 2,3-di-O-aryl-α,α′-trehalose glycolipid antigens, isolated from Mycobacterium fortuitum and Mycobacterium tuberculosis.

We also recommend Trading Suppliers and Manufacturers of cyclohexyl palmitate (cas 1673-08-1). Pls Click Website Link as below: cas 1673-08-1 suppliers

Prev:Cyclohexane oxidation and cyclohexyl hydroperoxide decomposition by poly(4-vinylpyridine-co-divinylbenzene) supported cobalt and chromium complexes
Next:A significant positive correlation between endogenous Trans-Zeatin (cas 1673-39-4) content and total arsenic in arsenic hyperaccumulator Pteris cretica var. nervosa)