A streamlined synthesis of β-hydroxy ketone substrates has been developed to further investigate a recently discovered cooperative Lewis base-mediated intramolecular carbonyl hydrosilylation reaction. The synthesis features an enone β-borylation/oxidation sequence that has proven to be quite general and high-yielding. This has allowed for additional investigations into the diastereoselectivity of the hydrosilylation reaction through the preparation of important polyketide fragments.
β-Hydroxyketones can be directly converted to cyclic disiloxanes using diphenylchlorosilane in the presence of imidazole and an amine base. The reaction is proposed to proceed via a nucleophilic activation mechanism through a cyclic chairlike transition state affording hydrosilylated products with high diastereoselectivity.
The hydroxy ketones (II), (X), and (XII), generated from enones by a convenient procedure, are found to undergo base‐mediated hydrosilylation with high diastereoselectivity.
A Masked-Alkene Metathesis-Based Synthesis of Isopulo'upone. -Masked triene substrates undergo Ru-catalyzed cross-metathesis according to A) to afford trienes after reductive elimination according to B). The utility of the process is demonstrated by the synthesis of precursor (XIIa) of racemic isopulo'upone (XIIb). -(CARTER, K. P.; MOSER, D. J.; STORVICK, J. M.; O'NEIL*, G. W.; Tetrahedron Lett. 52 (2011) 34, 4494-4496, http://dx.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.