1,5-Hydrogen Atom Transfer/Surzur–Tanner Rearrangement: A Radical Cascade Approach for the Synthesis of 1,6-Dioxaspiro[4.5]decane and 6,8-Dioxabicyclo[3.2.1]octane Scaffolds in Carbohydrate Systems

The 1,5-HAT–1,2-(ester)alkyl radical migration (Surzur–Tanner rearrangement) radical/polar sequence triggered by alkoxyl radicals has been studied on a series of C-glycosyl substrates with 3-C-(α,β-d,l-glycopyranosyl)1-propanol and C-(α-d,l-glycopyranosyl)methanol structures prepared from chiral pool d- and l-sugar. The use of acetoxy and diphenoxyphosphatoxy as leaving groups provides an efficient construction of 10-deoxy-1,6-dioxaspiro[4.5]decane and 4-deoxy-6,8-dioxabicyclo[3.2.1]octane frameworks. The alkoxyl radicals were generated by the reaction of the corresponding N-alkoxyphthalimides with group 14 hydrides [n-Bu3SnH(D) and (TMS)3SiH], and in comparative terms, the reaction was also initiated by visible light photocatalysis using the Hantzsch ester/fac-Ir(ppy)3 procedure. Special attention was devoted to the influence of the relative stereochemistry of the centers involved in the radical sequence on the reaction outcome. The addition of BF3•Et2O as a catalyst to the radical sequence resulted in a significant increase in the yields of the desired bicyclic ketals.

Bibliographic Details

Main Authors:	León, Elisa I., Martín, Ángeles, Montes, Adrián S., Pérez-Martín, Inés, Rodríguez, María del Sol, Suárez, Ernesto
Other Authors:	Ministerio de Economía y Competitividad (España)
Format:	artículo biblioteca
Language:	English
Published:	American Chemical Society 2021-11-05
Subjects:	Chemical structure, Hydrogen isotopes, Alcohols, Conformation, Organic compounds,
Online Access:	http://hdl.handle.net/10261/250968 http://dx.doi.org/10.13039/100012000 http://dx.doi.org/10.13039/501100003329
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