A General Method for the Synthesis of Sugar 2-C-Sulfonic Acids by 1 → 2 Arylthio Group Migration in Acid-Sensitive Thioglycosides. Direct Transformation of Thiotrityl Ethers into C-Sulfonic Acids

摘要

Fully protected triphenylmethyl 2-O-mesyl-1-thio-β-D-gluco- (14) and -α-D-mannopyranoside (28) were transformed by a stereoselective intramolecular 1 → 2 trans-arylthio migration into methyl 2-S-triphenylmethyl-α-D-manno- (15) and -β-D-glucopyranoside (29), respectively, using NaOCH_3 as nucleophile. The 2-S-triphenylmethyl ethers (15 and 29) were directly oxidized to sugar 2-C-sulfonic acids by using oxone (2KHSO_5, KHSO_4, K_2SO_4). Compounds (21, 23, 32, and 35) are the first representatives of secondary sugar C-sulfonic acids.