D-Erythronolactone from Mexico
D-Erythronolactone is a four-carbon sugar lactone with five-membered oxygen ring, under HTS 2932.20.50.50. Used in carbohydrate chemistry and as chiral building block.
Duty Rate — Mexico → United States
110%
Rate breakdown
9903.04.6096.3%Except as provided in heading 9903.04.61, patented pharmaceutical articles as provided for in subdivisions (c) and (d) of U.S. note 40 to this subchapter
9903.05.5510%Except for products described in headings 9903.05.85–9903.05.92 and 9903.05.94, articles the product of Mexico, as provided for in U.S. note 52 to this subchapter
Import Tips
• Optical rotation specification confirms D-isomer vs L-isomer classification
• Research chemical exemption may apply; include institutional end-user certificates
• HPLC purity certificate prevents mixture classification issues