Sugar surrogates

The Brimble group reported the synthesis of acortatarin A 20 in 2012. As in the first synthesis of acortatarin A 20 by Sudhakar et al. a traditional acid-catalyzed dehydrative spiroketalization was used as one of the final steps. However, instead of performing the previously used disconnection between CIO and N9, as several other groups have reporteda Maillard-type condensation reaction between amino alcohol 50 and the sugar surrogate 51 would be used to give 49. The amine 50 would come from D-mannitol and 51 would be prepared from furfuryl alcohol on a gram scale (Scheme l )" ... 

The most commonly used thiation reagents (see [166] for a discussion about thiation reagents) and particularly P4Sl0 and its surrogates are not suitable for acid-labile compounds. Some mild methods have been devised, for instance the conversion of nucleosides to thionucleosides [167], an example of which is given here. The nucleoside (protected on the sugar... 

Purines in which the sugar moiety is replaced by an abbreviated open-chain surrogate, for example, acyclovir, comprise an important group of antiviral drugs. Antiviral activity is retained when the pyrimidine ring in... 

Thioamides can serve as surrogates for isothiocyanates in the Marckwald synthesis. For example, reaction of a-amino acetals 1278 with thioamides 1277 in the presence of HgClz affords amidine intermediates, which cyclize to form imidazoles under acidic conditions. This method has been applied to synthesize a variety of sugar imidazoles (Scheme 324) <2005HCA10, 2004HCA3035, 2004HCA719, 2000TA435>. 

BHP) where a five carbon sugar-derived moiety is C-bound to the C30 pentacyclic hopane skeleton. This C5 unit may have additional sugar, amino acid, or other polar groups attached. It is hypothesized that BHP are the bacterial surrogates of sterols which perform a role as membrane modifiers in eukaryotic cells (Ourisson and Albrecht, 1992 Ourisson et ai, 1987). 

An useful consequence of the furan surrogate was its ability to promote exchange reactions of an anomeric methoxyl group with a variety of primary sugar alcohols . 

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