Reductive openings of benzylidene acetals. Kinetic studies of borane and alane activation by Lewis acids.

Summary, in English

The reaction kinetics for a number of reductive openings of methyl 2,3-di-O-benzyl-4,6-O-benzylidene-alpha-d-glucopyranoside have been investigated. Openings to give free HO-6 (using BH(3).THF-AlCl(3)-THF or LiAlH(4)-AlCl(3)-Et(2)O) follow first order kinetics, while reactions yielding free HO-4 (using BH(3).NMe(3)-AlCl(3)-THF or BH(3).NMe(3)-BF(3).OEt(2)-THF) follow higher order kinetics. The addition of water to the BH(3).NMe(3)-AlCl(3)-THF results in faster reactions. The BH(3).SMe(2)-AlCl(3)-THF system constitutes a borderline case, yielding both free HO-6 (by a first order reaction) and free HO-4 (by a higher order reaction). These results correlate well with the concept of regioselectivity by activation of borane complexes.

• Författare: Richard Johnsson; Risto Cukalevski; Fanny Dragén; Damir Ivanisevic; Ida Johansson; Linn Petersson; Erika Elgstrand Wettergren; Ka Bo Yam; Beatrice Yang; Ulf Ellervik
• Avdelning/ar: Centrum för analys och syntes; Institutionen för immunteknologi
• Publiceringsår: 2008
• Språk: Engelska
• Sidor: 2997-3000
• Publikation/Tidskrift/Serie: Carbohydrate Research
• Volym: 343
• Länkar: http://dx.doi.org/10.1016/j.carres.2008.08.022
• Dokumenttyp: Artikel i tidskrift
• Förlag: Elsevier
• Ämne: Organic Chemistry; Immunology in the medical area
• Status: Published
• ISBN/ISSN/Övrigt: ISSN: 1873-426X