Centro de Química, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal.
Amino Acids. 2012 Jun;42(6):2275-82. doi: 10.1007/s00726-011-0969-0. Epub 2011 Jul 8.
Aiming at the enhancement of the performance of (9-methoxy-3-oxo-3H-benzo[f]benzopyran-1-yl) methyl ester as photocleavable protecting group for the carboxylic acid function at long-wavelengths, 9-methoxy-3-thioxo-3H-benzo[f]benzopyran-L-valine and L-phenylalanine model conjugates were prepared through a thionation reaction of the corresponding oxo-benzobenzopyrans. These thioxobenzobenzopyran derivatives were subjected to photocleavage reactions in the same conditions as the parent oxo-benzobenzopyrans at different wavelengths of irradiation, and photocleavage data were obtained. It was found that the exchange of the carbonyl by a thiocarbonyl group enhanced the performance of the heterocyclic protecting group at 419 nm by improving the photolysis rates, making it an appropriate group for practical applications at long wavelengths.
为了提高（9-甲氧基-3-氧代-3H-苯并[f]苯并吡喃-1-基）甲酯作为羧酸功能在长波长下的光解保护基的性能，通过相应的氧杂苯并苯并吡喃的硫代反应制备了 9-甲氧基-3-硫代-3H-苯并[f]苯并吡喃-L-缬氨酸和 L-苯丙氨酸模型缀合物。这些硫代苯并苯并吡喃衍生物在与母体氧杂苯并苯并吡喃相同的条件下，在不同的辐照波长下进行光解反应，并获得光解数据。结果表明，通过提高光解速率，用硫羰基取代羰基可增强杂环保护基在 419nm 处的性能，使其成为长波长实际应用的合适基团。
