Competitive Silyl–Prins Cyclization versus Tandem Sakurai–Prins Cyclization: An Interesting Substitution Effect

Autor:	Alberto Diez-Varga, Francisco J. Pulido, Asunción Barbero, Alfonso González-Ortega, Héctor Barbero
Rok vydání:	2014
Předmět:	Mesylates Aldehydes Trimethylsilyl Compounds Allylic rearrangement Silylation Tandem Stereochemistry Organic Chemistry Substituent Stereoisomerism General Chemistry Prins reaction Catalysis Allyl Compounds chemistry.chemical_compound Trimethylsilyl trifluoromethanesulfonate chemistry Cyclization Alcohols Spiro Compounds Substitution effect Stereoselectivity
Zdroj:	Chemistry – A European Journal. 20:14112-14119
ISSN:	1521-3765 0947-6539
Popis:	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 (R(2)≠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.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::cacb8eb17e9a4f6606e9ba62cb88f549 https://doi.org/10.1002/chem.201403421 Zobrazit plný text záznamu Plný text ve formátu PDF Plný text ve formátu HTML
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