21962-24-3Relevant articles and documents
Direct C-4 arylation of crotonaldehyde with arenediazonium tetrafluoroborates
Zaragoza, Florencio,Heinze, Verena
scheme or table, p. 4678 - 4680 (2011/09/20)
Arenediazonium tetrafluoroborates react with crotonaldehyde (2-butenal) in methanol in the presence of catalytic amounts of Pd(OAc)2 to yield mainly 4,4-dimethoxy-1-butenylarenes. In most of the examples studied, small amounts of an isomeric byproduct were formed, presumably 3,3-dimethoxy-1- methylenepropylarenes. Because crotonaldehyde and arenediazonium salts are cheap and readily available, this reaction is a convenient access to protected 4-arylbutenals.
Enantioselective total synthesis of (-)-Clavosolide A and B
Son, Jung Beom,Kim, Si Nae,Kim, Na Yeong,Hwang, Min-Ho,Lee, Wonsun,Lee, Duck Hyung
scheme or table, p. 653 - 663 (2010/08/19)
Enantioselective total synthesis of (-)-clavosolide A and B was reported in full including the synthesis of proposed structure of (-)-clavosoldie A (1), revised structure of (-)-clavosoldie A (5), and revised structure of (-)-clavosoldie B (6). The relative and absolute stereochemistries of the natural products were confirmed unambiguously by comparing the optical rotation values and 1H and 13C NMR spectra of them.
Oxidation of Allylic Alcohols by Means of Electrochemical Methodology. Novel Rearrangement of Prenol under Direct Anodic Oxidation Conditions
Maki, Shojiro,Konno, Katsuhiro,Takayama, Hiroaki
, p. 559 - 560 (2007/10/03)
Electrochemical oxidation of naturally occurring allylic alcohols is described.Under direct anodic oxidation conditions, prenol 1 was readily oxidized, followed by rearrangement presumably on the surface of the anodic electrode, to give 3-hydroxy-2,2'-dimethyl-1,1'-dimethoxy propane 2 in high yield, whereas geraniol 5 afforded citral 6 under the same conditions.
A Convenient Method for the Preparation of Secondary Propargylic Ethers. The Reaction of Acetals with 1-Trimethylsilyl-1-alkynes Promoted by the Combined Use of Catalytic Amounts of Tin(IV) Chloride and Zinc Chloride
Hayashi, Masaji,Inubushi, Atsuro,Mukaiyama, Teruaki
, p. 4037 - 4042 (2007/10/02)
In the coexistence of catalytic amounts of SnCl4 and ZnCl2, acetals undergo a coupling with 1-trimethylsilylalkynes to give secondary propargilic ethers in good yields.Similarly, propargilic ethers are directly produced from aldehydes by the treatment with alkoxytrimethylsilanes and 1-trimethylsilylalkynes under the same conditions.This catalyst system also efficiently promotes aldol reaction of silyl enol ethers with acetals or aldehydes, and the Michael reaction of silyl enol ethers with α,β-unsaturated ketones.
Photo- and thermal isomerization of some 1-methoxyallyl cations
Childs, Ronald F.,Hagar, Mark E.
, p. 1788 - 1794 (2007/10/02)
The 1-methoxy-, 1-methoxy-3-methyl-, and 1-methoxy-2,3-dimethylallyl cations, 2, 5, and 9, were prepared by treatment of the dimethyl acetals of acrolein, crotonaldehyde, and tiglaldehyde, respectively, with FSO3H.Each of these ions was capable of existing in various stereoisomeric forms.The thermodynamically preferred conformation of 2, 5, and 9 all had a C1-O, E configuration and 5 and 9 an E configuration about the C2-C3 bonds.Irradiation of FSO3H solutions of these ions at -70 deg C using 254 nm light caused them to be converted to the other stereoisomers.Relatively efficient photoisomerism about both the C1-O and C2-C3 bonds was observed.The rates of the reverse thermal conversion of the photoproducts to 2, 5, and 9 were measured and on the basis of medium and substituent effects it was concluded that thermal isomerism about the C1-O bond takes place by an inversion process while stereomutation about the C2-C3 bond involves the addition of base to C3.
