A New Route To Sugar Alcohols

Abstract

Sugar alcohols have long been utilized in many commercial products as sugar alternatives that can present fewer health problems while retaining nearly the same sweetness. Sugar alcohol alternatives do not raise blood sugar nor do they cause tooth decay. Sugar alcohols contain vastly fewer calories than natural sugars due to their low digestibility, which at the same time is the basis of their negative effects. The non-digestible portion of the sugar alcohol can undergo fermentation by small bowel flora thus creating unwanted bloating and diarrhea. Reducing these side effects is an important motive for exploring new sugar alcohol isomers as well as inexpensive approaches to their laboratory synthesis. Sugar alcohols are currently synthesized by the reduction of natural sugars, but this process does not allow for controlling specific stereochemistry; and this could be the basis for their problematic digestibility. Using a different synthetic pathway that allows the control of stereochemistry of the sugar alcohol hydroxyl groups may produce new sugar alcohols that are resistant to fermentation. A methodological approach using aldol additions to cyclic ketones to produce higher order sugar alcohols will be investigated. Double aldol reactions would be expected to produce 7, 8 or 9-carbon sugar alcohols with specific isomers that have yet to be studied. Expanding this investigation to include cyclic ketones with bulky R-groups introduces another possibility for controlling stereochemistry. The ultimate result of this synthetic project would be a sugar alcohol homolog that can act as a viable low-calorie sweetener without gastrointestinal setbacks.