Hudson Lactone Rule

Name:
Hudson Lactone Rule
Detailed information:
The value of the rotation of aldonic acid lactones is decisively affected by the configuration of that carbon atom whose hydroxyl group is engaged in the cyclization. If, in the normal Fischer projection formula, the lactone ring is written on the right, the lactone is dextrorotatory; if it is written on the left, the lactone is levorotatory.