Ribofuranoside, ethyl 1-thio

The methyl, propyl, and benzyl 1-thio-a-D-glucofuranosides were prepared" by the original method (with neutralization by sodium hydroxide). Use of the method of Pacsu and Wilson" gave the methyl, ethyl, propyl, and isopropyl 1-thio-a-D-ribofuranosides in yields ranging from 65 to 80%. Sodium (methyl l-thio-a-D-glucofuranosid)uronate and the ethyl and propyl analogs were obtained 7 similarly from the sodium salt of the... 

Whereas ethyl l-thio-d-D-arabinofuranoside cannot be prepared directly, the 5-O-benzoyl diethyl dithioacetal gave 38% of ethyl 5-O-benzoyl-l-thio-0-D-arabinofuranoside, which was debenzoylated to the desired product. The 5-benzoate of ethyl 1-thio-a-D-ribofuranoside was similarly prepared.88 Two other compounds, ethyl 2-acetamido-2-deoxy-l-thio-/3-L-arabino-furanoside72 and ethyl 2-acetamido-2-deoxy-l-thio-a-D-xylofuranoside,73 were prepared from the corresponding d-galacto and d-gluco analogs by periodate oxidation, and subsequent borohydride reduction of the product. 

Selective activation of the phenyl selenoribofuranoside 195 in the presence of 1-thioribofuranoside acceptors was also studied.87 Surprisingly, reaction of 195 with benzylated ethyl 1 -thio-/3-D-ribofuranoside (202) afforded the product of trans glycosidation, 203 (Table VI). The same phenomenon... 

Et glycoside, tri-Ac Ethyl 2,3,5-tri-O-acetyl-1 -thio-a-D-ribofuranoside C13H20O7S 320.363 Mp 62°. [a]g +206 (c, 2.0 in CHCI3). Et glycoside, tribenzyl Ethyl 2,3,5-tri-O-benzyl-l-thio-a-D-ribofuranoside [160497-06-3]... 

Scheme 42). By contrast, the reaction of ) -D-glucopyranose penta-acetate with methyl tributyltin sulphide in the presence of an equimolar amount of tin(iv) chloride afforded the )3-anomer (251) stereospecifically and in high yield. This approach to alkyl 1-thioglycosides was shown to be applicable to furanose derivatives for example, the a- and jS-anomers of ethyl 2,3,5-tri-O-benzoyI-l-thio-D-ribofuranoside were obtained in a ratio of 2 3 when l-0-acetyI-2,3,5-tri-(9-benzoyl- -D-ribofuranose reacted with equivalent amounts of ethyl tributyltin sulphide and tin(iv) chloride at room temperature. 

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