PDF4PRO ⚡AMP

Modern search engine that looking for books and documents around the web

Example: stock market

Chapter 3 Protecting Groups - USU

1 Chapter 3: Protecting Groups I. Protecting Groups of Hydroxyl Groups Consider the stability and effect of anomeric group! Consider the solubility of starting material (the choice of solvent)! Consider the reactivity of different hydroxyl Groups ! * DCM is common for pyranoses with 2-3 OH s. For pyranose with more than 4 OH s, use DMF or pyridine. * Nucleophilicity of OH Groups on pyranoses (chair conformation) (Carbohydr. Res. 1987, 162, 159.) 1 OH > 2 OH Equatorial OH > axial OH Equatorial OH with vicinal axial OH (or OR) > Equatorial OH without vicinal axial OH (or OR) Examples: OOHHOHOHOOMe12346 Estimated order of nucleophilicity: 6-OH > 2-OH > 3-OH ~ 4-OH OOHHOHOHOOMe12346 Estimated order of nucleophilicity: 6-OH > 3-OH > 2-OH > 4-OH 2(i) Alkyl ether type SugOHS

1 Chapter 3: Protecting Groups I. Protecting Groups of Hydroxyl Groups Consider the stability and effect of anomeric group! Consider the solubility of starting material (the choice of solvent)!

Information

Domain:

Source:

Link to this page:

Please notify us if you found a problem with this document:

Spam in document Broken preview Other abuse

Transcription of Chapter 3 Protecting Groups - USU

Related search queries