Supplier Page from Thermo Fisher Scientific for Sulfur trioxide pyridine complex, technical, 48-50% active SO3
2-Mesitylenesulfonyl chloride, 99% from Thermo Fisher Scientific
D-Cystine, 98% from Thermo Fisher Scientific
Ethyl acetoacetate, 99%, pure from Thermo Fisher Scientific
meso-Erythritol, 99% from Thermo Fisher Scientific