1777-33-9Relevant articles and documents
Synthesis and Olfactory Properties of a 6′-Silasubstituted “Spiro[4.5]-δ-Damascone”
Lovchik, Martin A.,Kraft, Philip
, p. 4590 - 4596 (2017)
The silicon analogue of the potent spirocyclic δ-damascone odorant 6 was synthesized from allyltrichlorosilane (15) and but-2-en-1-ol (16). The latter was transformed to 3-methylpen-4-enenitrile (11) by Saucy–Marbet reaction with ethoxyethane and subsequent treatment with HONH2?HCl. The resulting γ,δ-unsaturated nitrile 11 was silylated with 1-allyl-1-chlorosilolane (14), which was prepared from allyltrichlorosilane (15) and the bis-Grignard reagent of 1,4-dichlorobutane. Metathetic ring closure employing the Grubbs I catalyst, followed by DIBAL reduction with non-aqueous work up, Grignard reaction with prop-1-en-1-ylmagnesium bromide, and Attenburrow MnO2 oxidation concluded the synthesis. The target compound was found to be olfactorily related to the spiro[4.5]-δ-damascone lead, but approximately 900 times weaker. In a type of enol Brook rearrangement, it thermally decomposes however to 3,6-dihydro-2H-1,2-oxasilocine (20), which surprisingly is a damascone odorant as well; although, 12 000 times weaker.
APPROACHES TO THE SYNTHESIS OF ASPIDOSPERMA ALKALOIDS. PART I. PRELIMINARY STUDIES IN THE VINCADIFFORMINE GROUP.
Costello, Gerard,Saxton, J. Edwin
, p. 6047 - 6069 (1986)
As a preface to work leading to the total synthesis of 18,19-dehydrotabersonine, described in the following paper, some older work on the synthesis of (+/-)-3-oxo-20-desethyl-20-allylvincadifformine, its C-20 epimer, and (+/-)-3-oxo-19-vinylvincadifformine is reported.Attempts to convert these compounds, by appropriate manipulation of the isolated double bond, into a wide range of anilinoacrylate alkaloids, e.g. minovincine, tuboxenine, and pseudokopsinine, are described.Methods for the functionalisation of the double bond at an earlier stage in the synthesis, e.g. using 3,18-dioxo-1-demethylvincatine, have also been investigated.
Photocatalytic One-Pot Synthesis of Homoallyl Ketones via a Norrish Type i Reaction of Cyclopentanones
Okada, Megumi,Yamada, Keiichi,Fukuyama, Takahide,Ravelli, Davide,Fagnoni, Maurizio,Ryu, Ilhyong
, p. 9365 - 9369 (2015/09/28)
A photocatalytic synthesis of homoallyl ketones was achieved via a one-pot procedure starting from a Norrish Type I reaction of cyclopentanones, followed by a decatungstate-catalyzed hydroacylation of electron-deficient olefins by the resulting 4-pentenals. The site-selective formyl H-abstraction in the second step can be explained by radical polar effects in the transition state.
