Concise Entry to Both Enantiomers of 8-Oxabicyclo[3.2.1]oct-3-en-2-one Based on Novel Oxidative Etherification: Formal Synthesis of (+)-Sundiversifolide
摘要:
Both enantiomers of 8-oxabicyclo[3.2.1]oct-3-en-2-one (6) have been synthesized from 4-hydroxycyclohept-2-enone (3) on the basis of a novel oxidative cyclo-etherification using PhI(OH)OTs (Koser's reagent). (-)-(1S,5R)-8-Oxabicyclo[3.2.1]oct-3-en-2-one [(-)-6, 95% ee] was expeditiously transformed to (-)-sundiversifolide (1).
Continuous Endoperoxidation of Conjugated Dienes and Subsequent Rearrangements Leading to C–H Oxidized Synthons
作者:Juliana M. de Souza、Timothy J. Brocksom、D.Tyler McQuade、Kleber T. de Oliveira
DOI:10.1021/acs.joc.8b01307
日期:2018.8.3
We have investigated the continuous flow photooxidation of several conjugated dienes and subsequent rearrangement using a practical and safe continuous-flow homemade engineered setup. End-to-end approaches involving endoperoxidation, Kornblum–DeLaMare rearrangement, and additional rearrangements are comprehensively detailed with optimization, scope, and scale-up to obtain useful hydroxyenones, furans
An unprecedented photoinduced azide–alkene cycloaddition has been developed, the key elements of which include the photoisomerization of cis-cycloheptenone to trans-cycloheptenone, strain-promoted 1,3-dipolar cycloaddition of trans-cycloheptenone with azide, and aerobic oxidative aromatization of the resulting 1,2,3-triazoline. The newly developed photoclick reactions display several appealing features
A One-Pot, Base-Free Annelation Approach to α-Alkylidene-γ-butyrolactones
作者:Russell R. A. Kitson、Richard J. K. Taylor、John L. Wood
DOI:10.1021/ol902191d
日期:2009.11.19
A novel annelation procedure has been developed for the conversion of γ-hydoxy enones into α-alkylidene-γ-butyrolactones. This one-pot method utilizes the Bestmann ylide (triphenylphosphoranylideneketene) and proceeds by way of acylation followed by an intramolecular conjugate addition/proton transfer/Wittig olefination sequence. The procedure is “base-free” and is useful for the preparation of a range
Palladium(0) catalyzed reaction of 1,3-diene 1,4-epiperoxides
作者:M. Suzuki、Y. Oda、R. Noyori
DOI:10.1016/s0040-4039(01)82971-3
日期:1981.1
Reaction of 1,3-diene 1,4-epiperoxides with Pd(PPh3)4 catalyst forms the corresponding 4-hydroxy enones, syn diepoxides, and 1,4-diols as the major products. The results are interpreted as being due to competing Pd(0)/Pd(II) and Pd(0)/Pd(I) exchange mechanisms.
The Preparation of α-Alkylidene-γ-Butyrolactones Using a Telescoped Intramolecular Michael/Olefination (TIMO) Sequence: Synthesis of (+)-Paeonilactone B
作者:Michael G. Edwards、Martin N. Kenworthy、Russell R. A. Kitson、Alexis Perry、Mark S. Scott、Adrian C. Whitwood、Richard J. K. Taylor
DOI:10.1002/ejoc.200800558
日期:2008.10
A novel telescopedintramolecularMichael addition/proton transfer/HWE olefination sequence has been developed to provide rapid access to α-alkylidene-γ-butyrolactones. This methodology has been applied to prepare a range of tetrahydrobenzofuran-2,5-diones, and related systems, and also utilised in an extremely short synthesis of the natural product (+)-paeonilactoneB in enantiomerically pure form