2026-05-05T19:46:26Zhttps://uvadoc.uva.es/oai/request

oai:uvadoc.uva.es:10324/662562025-02-21T08:48:31Zcom_10324_28708com_10324_954com_10324_894com_10324_28542com_10324_952com_10324_1186com_10324_931col_10324_28709col_10324_28543col_10324_1404

00925njm 22002777a 4500 dc Diez De La Varga, Alberto author Barbero San Juan, Héctor author Pulido Pelaz, Francisco José author González Ortega, Alfonso author Barbero Pérez, María Asunción author 2014 Two different mechanism pathways are observed for the reaction of allylsilyl alcohols 1 and aldehydes in the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf). In the case of allylsilyl alcohols without allylic substituents, the reaction gives dioxaspirodecanes, which are the products of a tandem Sakurai–Prins cyclization. In contrast, allylsilyl alcohols with an allylic substituent (R2¼6 H) selectively provide oxepanes, thus corresponding to a direct silyl–Prins cyclization. Both types of product are obtained with excellent stereoselectivity. Theoretical studies have been performed to obtain some rationalization for the observed stereoselectivity. Chem. Eur. J. 2014, 20, 14112 – 14119 0947-6539 https://uvadoc.uva.es/handle/10324/66256 10.1002/chem.201403421 14112 43 14119 Chemistry – A European Journal 20 1521-3765 Competitive Silyl–Prins Cyclization versus Tandem Sakurai–Prins Cyclization: An Interesting Substitution Effect