2026-04-28T19:29:52Zhttps://uvadoc.uva.es/oai/requestoai:uvadoc.uva.es:10324/592132023-04-19T19:00:33Zcom_10324_1187com_10324_931com_10324_894col_10324_1408
Díez Poza, Carlos
Barbero Pérez, María Asunción
2023-04-19T11:09:10Z
2023-04-19T11:09:10Z
2021
Molecules, 2021, Vol. 26, Nº. 23, 7386
1420-3049
https://uvadoc.uva.es/handle/10324/59213
10.3390/molecules26237386
7386
23
Molecules
26
1420-3049
The regioselective ring opening of epoxy alcohols is an effective method for the synthesis of different types of oxacycles. The 5-exo opening being preferred vs. the 6-endo mode, according to Baldwin rules, the use of silyl-substituted oxiranes has been reported as a possible method to favor the 6-endo cyclization. However, there is a need for a detailed study on the different factors (structural factors, catalyst nature or conditions) that influence this process. In this paper, the acid-catalyzed cyclization of epoxysilyl alcohols was studied, focusing on the effect of substituents and reaction conditions on the outcome of the process. Two types of heterocycles (tetrahydrofurans or tetrahydropyrans) were selectively obtained depending on the structure of the initial epoxysilyl alcohol. Interestingly, cyclization of hindered epoxysilyl alcohols mainly proceeds through an unexpected side reaction, which implies a previous isomerization to an aldehyde. A mechanistic proposal for the formation of the different products is presented.
eng
info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by/4.0/
© 2021 The authors
Atribución 4.0 Internacional
Química orgánica
Organic chemistry
Influence of the substituents on the opening of silylepoxy alcohols: 5-exo-cyclization towards tetrahydrofurans vs. unexpected side reaction leading to tetrahydropyrans
info:eu-repo/semantics/article