A catalyst don`t appear in the overall stoichiometry of the reaction it catalyzes, but it must appear in at least one of the elementary reactions in the mechanism for the catalyzed reaction. category: Tetrahydropyranscategory: Tetrahydropyrans, , Name is 2,3,4,6-Tetra-o-acetyl-D-glucopyranose, molecular formula is C14H20O10. In a patent, introducing its new discovery.
The reaction of (E)-1-(2?-3?,4?,6?-tetra-O-acetyl-beta-D-glucopyranosy loxy)-3-(trimethylsiloxy)buta-1,3-diene 1 and maleic anhydride gives cycloadduct 10 and ketone 12. Reduction of ketone 13, formed by acidic hydrolysis of silyl enol ether 10, with sodium cyanoborohydride in acetic acid gives an 83: 17 mixture of the gamma- and delta-lactone 14 and 15. gamma-Lactone 14 is transformed into the aminomonocarba-disaccharide, 4-acetamido-2,4-dideoxy-3-O-(beta-D-glucopyranosyl)-5a-carba-beta-L-lyxo-hex opyranose 7, using a five-step procedure involving the Curtius rearrangement of acyl azide 16. A similar sequence using gamma-lactone 21, prepared from ketone 12, gives the protected aminomonocarbadisaccharide, 4-acetamido-1,6-di-O-acetyl-2,4-dideoxy-3-O-(2?,3?,4?,6? -tetra-O-acetyl-beta-D-glucopyranosyl)-5a-carba- beta-D-lyxo-hexopyranose 8. Reaction of cycloadduct 10 with dimethyldioxirane gives acyloin 26. Acetylation under acidic conditions followed by reduction with sodium cyanoborohydride in acetic acid gives a 75: 25 mixture of the gamma- and delta-lactone 28 and 29. Using a sequence similar to that employed for the preparation of compounds 7 and 8, gamma-lactone 28 is converted into the fully substituted aminomonocarba-disaccharide, 4-acetamido-1,2,6-tri-O-acetyl-4-deoxy-3-O-(2?,3?,4?,6?- tetra-O-acetyl-beta-D-glucopyranosyl)-5a-carba-beta-L-galactopyranose 9.
Balanced chemical reaction does not necessarily reveal either the individual elementary reactions by which a reaction occurs or its rate law.category: Tetrahydropyrans. In my other articles, you can also check out more blogs about 10343-06-3
Reference：
Tetrahydropyran – Wikipedia,
Tetrahydropyran – an overview | ScienceDirect Topics