Acrylates, synthesis from sugars

The synthesis of acrylates from sugars and other substrates has been applied in the early phases of enzymatic reactions and has already been reviewed [2, 14]. The method is attractive because the enzyme allows for mild and, in some examples, stereoselective acrylation. A recent example was published by Popescu et al. who took advantage of the frequent transesterification reactions and reported a route to highly functional linear copoly(meth)acrylates [15]. Methyl (meth)acrylate was mixed with various functional alcohols in the presence of Novozym 435. In situ... 

All the theoretically predictable sixteen racemic pseudo-sugars have been synthesized, as well as the ten enantiomers. The most accessible starting material for the synthesis was the Diels-Alder adduct 33 of furan and acrylic acid. Furthermore, the adduct 33 was readily resolved by means of optically active a-methylbenzylamines into the two antipodes 86 and 87, which were also used for the preparation of enatiomeric pseudosugars. A chiral synthesis from true sugars was another prominent method for the preparation of the enantiomers. The remaining twenty two unknown enantiomeric pseudo-sugars will be prepared by either one of the two methods in the near future. 

Synthesis of bicyclic aza sugars from D-xylose was reported. A key step involved reaction of the nitrone 9 with ethyl acrylate providing intermediate 10, which was finally converted into aza sugars (Fig. 4).11... 

Levulinic acid is formed by the treatment of six-carbon sugar carbohydrates from starch or lignocellulosics with acids, or by add treatment plus a reductive step of five-carbon sugars derived from hemicellulose. Levulinic add can serve as a building block for the synthesis of many derivatives of interest may be the selective oxidation to succinic and acrylic add. [i-Acetylacrylic add could be used in the production of new acrylate polymers. 

The chiral moiety of the nitrone can also be located at the carbon atom. Yokoyama et al. [50] used this approach in the asymmetric synthesis of spiro isoxazohdines (Scheme 10.21). The ribose-derived nitrone 62 is obtained from the corresponding oxime by Michael addition to methyl acrylate. With a second equivalent of methyl acrylate, the sugar nitrone 62 gave a single cycloadduct 63, which was converted into the corresponding pyrrolidine by reduction. 

Although already discovered in 1780 by the Swedish chemist Carl Wilhelm Scheele,who isolated the lactic acid from sour milk, lactic acid has attracted more recently a great deal of attention due to its widespread applications, mainly in food, chemical, cosmetic, and pharmaceutical industries. Also, it has a great potential for the production of biodegradable and biocompatible polylactic acid (PLA) and, besides 3-hydroxypropionic acid, as an intermediate for sugar-based acrylic acid. Lactic acid production can be achieved either by chemical synthesis routes or by fermentative production (lactic acid fermentation). By the chemical synthesis route, a racemic mixture of DL-lactic acid is usually... 

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