THE PREBIOTIC SYNTHESIS OF CARBOHYDRATES - A REASSESSMENT

Questions concerning the significance of previous work on the formose reaction have led us to reexamine the question of the prebiotic synthesis of sugars. The results of new experiments lead to the following conclusions: The formose reaction is a geochemically plausible reaction which depends on neither basic conditions nor on the presence of trace amounts of carbohydrate impurities. However, this process is not a plausible source of ribose nor of any other individual sugar. In contrast to the nonspecific formation of complex mixtures of sugars via the formose reaction, the reduced sugar pentaerythritol is formed with great selectivity by the ultraviolet irradiation of 0.1 M formaldehyde. This compound may have played an important role in chemical evolution.