Furanose Sugar Derivative from Mexico
Methyl furanoside derivatives feature five-membered oxygen heterocyclic rings from sugar cyclization, used as glycosyl donors in carbohydrate synthesis. Excluded from sugar headings by Chapter 29 priority, classified 2932.99.90.90. Qualifies as chemically defined heterocyclic oxygen compound.
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
• NMR spectra confirming furanose anomeric configuration required
• Reducing sugar test negative prevents classification under Chapter 17
• Protecting group analysis essential for multi-step synthesis intermediates