Stereoelectronic Control in Regioselective Carbohydrate Protection
2012 (English)In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 77, no 3, 1457-1467 p.Article in journal (Refereed) Published
Organotin-mediated regioselective protection has been extensively used in organic synthesis for many years. However, the mechanistic origin of the resulting regioselectivity is still not clear. By the comparison of the steric and stereoelectronic effects controlling the geometry of five-membered rings formed from neighboring group participation, from intramolecular acyl group migration, or from orthoester transesterification on pyranoside rings, a theory on the pattern resulting from the reaction with dibutyltin oxide is presented. It is thus suggested that the regioselectivity of organotin-mediated protection is controlled by analogous steric and stereoelectronic effects as in neighboring group participation and acyl group migration, mainly dependent on the stereoelectronic effects of the pyranoside itself, and not related to complex stannylene structures. An organotin protection mechanism is also suggested, emanating from steric and stereoelectronic effects, nucleophilicity, and organotin acyl migration.
Place, publisher, year, edition, pages
2012. Vol. 77, no 3, 1457-1467 p.
IdentifiersURN: urn:nbn:se:kth:diva-93013DOI: 10.1021/jo202336yISI: 000300462700024ScopusID: 2-s2.0-84863011246OAI: oai:DiVA.org:kth-93013DiVA: diva2:514876
FunderSwedish Research Council
QC 201204112012-04-112012-04-102012-04-11Bibliographically approved