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Organotitanium-induced stereoselective alkylative endo-cleavage of benzyl pentopyranosides

Olsson, Roger LU ; Rundström, Pontus ; Persson, Björn LU and Frejd, Torbjörn LU (1998) In Carbohydrate Research 307(1-2). p.13-18
Abstract

The results presented are the first examples where organotitanium reagents induced alkylative endo-cleavage of carbohydrates. The best conditions for the alkylative transfer of a methyl group to benzyl 2-deoxy- 2-C-methyl-4-O-(tert-butyldimethylsilyl)-α-D-arabinopyranoside (1) were the application of one equivalent of AlMe3 followed by four equivalents of MeTiCl3 generated by mixing TiCl4 and ZnMe2 in a ratio 2:1, or, alternatively, treatment of I with two equivalents of 1:1 Me2TiCl2-ZnMe2. Both the yields and diastereoselectivities were comparable with those of the reaction with AlMe3 but the titanium reagents were more reactive and could be applied... (More)

The results presented are the first examples where organotitanium reagents induced alkylative endo-cleavage of carbohydrates. The best conditions for the alkylative transfer of a methyl group to benzyl 2-deoxy- 2-C-methyl-4-O-(tert-butyldimethylsilyl)-α-D-arabinopyranoside (1) were the application of one equivalent of AlMe3 followed by four equivalents of MeTiCl3 generated by mixing TiCl4 and ZnMe2 in a ratio 2:1, or, alternatively, treatment of I with two equivalents of 1:1 Me2TiCl2-ZnMe2. Both the yields and diastereoselectivities were comparable with those of the reaction with AlMe3 but the titanium reagents were more reactive and could be applied at much lower temperatures than the aluminium reagent.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Alkylation, Endo-cleavage, Organotitanium reagents, Pentopyranosides
in
Carbohydrate Research
volume
307
issue
1-2
pages
13 - 18
publisher
Elsevier
external identifiers
  • scopus:0032004261
ISSN
0008-6215
DOI
10.1016/S0008-6215(97)10079-9
language
English
LU publication?
yes
id
3f200302-25c5-4b0d-9e14-bf56d863988a
date added to LUP
2019-10-02 10:54:52
date last changed
2020-01-13 02:26:23
@article{3f200302-25c5-4b0d-9e14-bf56d863988a,
  abstract     = {<p>The results presented are the first examples where organotitanium reagents induced alkylative endo-cleavage of carbohydrates. The best conditions for the alkylative transfer of a methyl group to benzyl 2-deoxy- 2-C-methyl-4-O-(tert-butyldimethylsilyl)-α-D-arabinopyranoside (1) were the application of one equivalent of AlMe<sub>3</sub> followed by four equivalents of MeTiCl<sub>3</sub> generated by mixing TiCl<sub>4</sub> and ZnMe<sub>2</sub> in a ratio 2:1, or, alternatively, treatment of I with two equivalents of 1:1 Me<sub>2</sub>TiCl<sub>2</sub>-ZnMe<sub>2</sub>. Both the yields and diastereoselectivities were comparable with those of the reaction with AlMe<sub>3</sub> but the titanium reagents were more reactive and could be applied at much lower temperatures than the aluminium reagent.</p>},
  author       = {Olsson, Roger and Rundström, Pontus and Persson, Björn and Frejd, Torbjörn},
  issn         = {0008-6215},
  language     = {eng},
  number       = {1-2},
  pages        = {13--18},
  publisher    = {Elsevier},
  series       = {Carbohydrate Research},
  title        = {Organotitanium-induced stereoselective alkylative endo-cleavage of benzyl pentopyranosides},
  url          = {http://dx.doi.org/10.1016/S0008-6215(97)10079-9},
  doi          = {10.1016/S0008-6215(97)10079-9},
  volume       = {307},
  year         = {1998},
}