Dextra Laboratories (United Kingdom)

Gemcitabine, 2′-deoxy-2′,2′-difluorocytidine, is currently prescribed against a number of cancers. Here we report a linear synthesis of gemcitabine with a high-yielding direct conversion of 3,5-di-O-benzoyl-2-deoxy-2,2-difluororibose into the corresponding glycosyl urea as the key step, followed by conventional conversion to the cytosine base via the uracil derivative. The process proceeded with modest anomeric selectivity.

The crystal structure unequivocally confirms the relative stereochemistry of the title compound, C6H11FO5. The absolute stereochemistry was determined by the use of d-galactose as the starting material. The compound exists as a three-dimensional O—H⋯O hydrogen-bonded network with each mol­ecule acting as a donor and acceptor for four hydrogen bonds.

Starch is an important ingredient in a wide range of foods. It is used as a thickener, to adjust texture, to improve appearance or to act as a filler. The starch industry also supplies a diverse range of non-food industries with starch and starch derivatives. These markets account for almost half of the total production of the European starch Industry, but only 25% of the total UK starch supply. Of the 216 221 † of starch used for Industrial markets in the UK, 30% is imported potato starch, 57% is maize starch processed in the UK from imported maize, and only 13% is wheat starch, which may be both grown and processed in the UK. This article surveys some of the industrial markets for starch, highlighting recent changes which have occurred and pinpointing areas of potential development which may increase non-food use of UK-grown starch in the future. This article is based on the findings of a LINK project which was funded under the Crops for Industrial Use Programme by the BBSRC, EPSRC, SOAFD, HGCA and PMB.