72402-00-7Relevant articles and documents
The magnesium-ene cyclization stereochemically directed by an allylic oxyanionic group and its application to a highly stereoselective synthesis of (±)-matatabiether. Allylmagnesium compounds by reductive magnesiation of allyl phenyl sulfides
Cheng,Zhu,Yu,Cohen
, p. 30 - 34 (2007/10/03)
The first example of a magnesium-ene cyclization stereochemically directed by an allylic oxyanionic group is demonstrated by a highly stereoselective synthesis of the bicyclic terpene matatabiether 10. The synthetic method is particularly valuable, not only because of the stereochemical control and the utility of the versatile hydroxyl group introduced into the product, but also because the precursor of the allylmagnesium is an allyl phenyl sulfide, which is more stable and more easily prepared in a connective fashion than the usual allyl halide precursor. Since the presence of lithium ions encourages undesirable proton transfer to the cyclized organometallic and is detrimental to the stereochemical control, the conversion of the allylic thioether to the allylmagnesium utilizes a lithium-free method involving direct reductive magnesiation in the presence of the magnesium-anthracene complex.
Total Synthesis of the Pseudoguaianolide (+)-Confertin
Quinkert, Gerhard,Schmalz, Hans-Guenther,Walzer, Egon,Gross, Stefan,Kowalczyk-Przewloka, Teresa,et al.
, p. 283 - 316 (2007/10/02)
The first total synthesis of the pseudoguaianolide (+)-confertin (1) begins with the preparation of the enantiomerically pure cyclopropane derivative 6b and its stereospecific ring expansion furnishing the five-membered ring A-building block 8a.The AB ketone 21d is produced by intermolecular Michael addition, Lewis acid catalyzed intramolecular hetero-ene reaction, and a pair of oxidation/reduction reactions.Fusion of the heterocyclic five-membered ring and α-methylenation of the ABC intermediate 35c is accomplished by well-known technology.The structure of essential synthetic intermediates has been determined by 2D-NMR, CD spectroscopy, or single crystal X-ray analysis.The whole synthesis starts from α-chloroacetone and reaches the target compound 1 after 22 steps.
Stereoselective Syntheses of 3-Acetyl-1,2-dimethyl-1-cyclopentanols. Syntheses of dl-Plinols A, B, and C
Imagawa, Takeshi,Matsuura, Kazuyuki,Murai, Nobuyuki,Akiyama, Tetsuo,Kawanisi, Mituyosi
, p. 3020 - 3022 (2007/10/02)
c- and t-3-Acetyl-1,c-2-dimethyl-r-1-cyclopentanols and c-3-acetyl-1,t-2-dimethyl-r-1-cyclopentanol are synthesized stereoselectively and dl-plinols A, B, and C are prepared therefrom.
