Mannopyranoside, methyl

Mannopyranoside, methyl a-D-3,4,6-tri-0-acetyl-2-deoxy-2-thiocyanato- syrup +79.3 37... 

The less acidic hydroxyl groups being more reactive in this alkylation sequence [1661, the 3-benzyl ethers dominate in the reaction of 2,3-diols, and 4-benzyl ethers in the case of 4,6-diols. Thus, 95 % of methyl 3-0-benzyl-4,6-O-benzylidene-a-D-manno-pyranoside together with 5 % of unreacted starting material have been obtained from methyl 4,6-O-benzylidene-a-D-mannopyranoside. Methyl 2,3-0-isopropylidene-sodium hydride in 1,2-dimethoxy-... 

Methyl a-D-mannopyranoside Methyl 2-acetamido-2-deoxy-a-D-glucopyranoside 0.5 1.0... 

Methyl-3,4,6-tri-0-acetyl-2-per-chlorato-mercuri- E14a/3, 802 [En + H3C — 0H/Hg(C104)2] 2-Deoxy-/l-n-mannopyranosid Methyl-3,4,6-tri-O-acetyl-2-per-chlorato-mercuri- E14a/3, 802 [En + H3C-0H/Hg(C104)J... 

Apparently the first definite assignment of a chair form to a six-membered, cyclic-acetal ring was made in order to explain the occurrence of only one stable isomer of methyl 4,6-0-benzylidene-,8-D-glucopyranoside, which will have the conformation L. The stable forms of 4,6-0-benzyli-dene derivatives of methyl /3-D-mannopyranoside, methyl 8-D-allopyrano-side, and methyl S-D-altropyranoside will differ from L only in the configurations at C2 and 03. "... 

---