In this study, a general, efficient, and simple methodology for biocatalytic reduction of carbonyl compounds such as acetophenone 1a and 4-chloroacetophenone 2a using freshly cut ripen fruit of fresh pumpkin in the aqueous medium at room temperature was reported. The prochiral ketones can be reduced to chiral secondary alcohols in a generalized way. The obtained results indicated that the pumpkin fruits could be used as biochemical catalysts to contribute to the preparation of many pharmaceutical alcohols. This biochemical catalyst attracted much attention because of the low cost, high efficiency, and special selectivity for its environmental friendliness and its contribution to certain recommended green chemistry principles.
In this research, our aim was to contribute to this area by using biochemical catalysts with plant sources such as the pumpkin fruits in different states (fresh, juice). The prochiral ketones: acetophenone and 4-chloroacetophenone were chosen as typical ketones and the yield and optical purity were 77-88% and 50-96%, respectively. Mild reaction condition, simple operation, and easy availability of fresh pumpkin fruit revealed this protocol as an attractive and alternative eco-friendly option for a general reduction of all types of carbonyl compounds.