A General Strategy for the Stereocontrolled Preparation of Diverse 8- and 9-Membered Laurencia-Type Bromoethers
摘要:
A unique procedure to effect a ring-expanding bromoetherification process is described, wherein tetrahydrofurans and tetrahydropyrans are smoothly transformed into 8- and 9-membered bromoethers in a regio- and stereocontrolled manner through the use of BDSB (bromodiethylsulfonium bromopentachloroantimonate). These products resemble the cores of the Laurencia C15 acetogenins. In light of the generality and effectiveness of the approach, this work provides a unique strategy for their laboratory preparation and may implicate a possible biosynthesis pathway.
A General Strategy for the Stereocontrolled Preparation of Diverse 8- and 9-Membered Laurencia-Type Bromoethers
摘要:
A unique procedure to effect a ring-expanding bromoetherification process is described, wherein tetrahydrofurans and tetrahydropyrans are smoothly transformed into 8- and 9-membered bromoethers in a regio- and stereocontrolled manner through the use of BDSB (bromodiethylsulfonium bromopentachloroantimonate). These products resemble the cores of the Laurencia C15 acetogenins. In light of the generality and effectiveness of the approach, this work provides a unique strategy for their laboratory preparation and may implicate a possible biosynthesis pathway.
The present invention relates to compounds of formula (I) as properfume compounds. In particular, the present invention relates to a method to release a compound being a carbonyl of formula (II), a formate ester of formula (III) and/or an alcohol of formula (IV), by exposing the compound of formula (I) to an environment wherein it is oxidized. Moreover, the present invention relates to a perfuming composition and a perfumed consumer product comprising at least one compound of formula (I).
Improved Cope-type hydroamination reactivity of hydrazine derivatives
作者:Francis Loiseau、Christian Clavette、Michaël Raymond、Jean-Grégoire Roveda、Alishya Burrell、André M. Beauchemin
DOI:10.1039/c0cc02403a
日期:——
A systematic investigation on the metal-free, Cope-type hydroamination reactivity of hydrazides and analogues is reported. Optimization of the hydrazide structure resulted in more facile intramolecular reactivity and enabled intermolecular reactions of alkenes, thus providing a direct approach to polysubstituted hydrazides.
Four newsigmatropicsequences triggered by the regiocontrolled [2,3]-Wittig rearrangement of unsymmetrical bis-allylic ethers (1) to the l,5-dien-3-ols (2) arc described, which provide unique, regiocontrolled methods for the synthesis of a wide variety of unsaturatedcarbonylcompounds possessing interesting molecular frameworks. The newly developed sequences include the [2,3]-Wittig-Claisen, the
APPLICATIONS OF THE TANDEM [2,3]-WITTIG-OXY-COPE REARRANGEMENT TO SYNTHESES OF<i>exo</i>-BREVICOMIN AND OXOCRINOL. THE SCOPE AND LIMITATION OF THE SIGMATROPIC SEQUENCES AS A SYNTHETIC METHOD FOR δ,ε-UNSATURATED KETONES
作者:Koichi Mikami、Takeshi Nakai
DOI:10.1246/cl.1982.1349
日期:1982.9.5
The synthetic utility of the title sigmatropicsequence is illustrated in the syntheses of E-6-nonen-2-one, a precursor of exo-brevicomin, and oxocrinol. The scope and limitation of this sequence as a synthetic method for δ,e-unsaturated ketones are also discussed.