Total synthesis of (−)-ephedradine A: an efficient construction of optically active dihydrobenzofuran-ring via C–H insertion reaction

Tetrahedron ◽  
2004 ◽  
Vol 60 (43) ◽  
pp. 9615-9628 ◽  
Author(s):  
Wataru Kurosawa ◽  
Hideki Kobayashi ◽  
Toshiyuki Kan ◽  
Tohru Fukuyama
2002 ◽  
Vol 74 (1) ◽  
pp. 159-166 ◽  
Author(s):  
Iwao Ojima

Recent development in the transition metal-catalyzed cyclization reactions for organic syntheses in the author's laboratories is summarized, which includes (i) novel silylcarbocyclizations (SiCaCs) and carbonylative carbotricyclizations, (ii) intramolecular silylformylations and desymmerization of siloxydiynes by sequential double silylformylation, (iii) efficient total synthesis of (+)-prosopinine, (iv) enantioselective desymmetrization of aminodienes, and (iv) new and efficient routes to 1-azabicyclo[x.y.0]alkane amino acids. All these processes are catalyzed by Rh or Rh­Co complexes, and useful for rapid and efficient construction of a variety of heterocyclic and carbocyclic compounds. Mechanisms of these new carbocyclization and cyclohydrocarbonylation reactions are also discussed.


Synlett ◽  
2020 ◽  
Vol 32 (01) ◽  
pp. 45-50
Author(s):  
Udo Nubbemeyer ◽  
Analuisa Nava ◽  
Lukas Trippe ◽  
Andrea Frank ◽  
Lars Andernach ◽  
...  

AbstractStarting from methyl cycloheptatrienyl-1-carboxylate, 6-acylation was successfully achieved employing glutaryl chloride in the presence of AlCl3 under controlled reaction conditions to furnish keto carboxylic acid product. After protection of this keto carboxylic acid as tert-butyl ester, reagent-controlled enantioselective reductions delivered configuration-defined methyl-6-hydroxylalkyl cycloheptatriene-1-carboxylates with up to 80% ee. Whereas simple NaBH4 reduction of the keto carboxylic acid and subsequent lactonization afforded a methyl-6-tetrahydropyranonyl cycloheptatriene-1-carboxylate. Resolution using chiral HPLC delivered the product enantiomers with up to >99% ee Finally, ECD analyses enabled structure elucidation. The products are used as key intermediates in enantioselective 6,11-methylene-lipoxin B4 syntheses.


Tetrahedron ◽  
1999 ◽  
Vol 55 (24) ◽  
pp. 7461-7470 ◽  
Author(s):  
Takayuki Yakura ◽  
Akiharu Ueki ◽  
Tsuyoshi Kitamura ◽  
Kenji Tanaka ◽  
Masatake Nameki ◽  
...  

ChemInform ◽  
2010 ◽  
Vol 27 (34) ◽  
pp. no-no
Author(s):  
T. YOSHINO ◽  
Y. NAGATA ◽  
E. ITOH ◽  
M. HASHIMOTO ◽  
T. KATOH ◽  
...  

ChemInform ◽  
2010 ◽  
Vol 26 (34) ◽  
pp. no-no
Author(s):  
H. YOSHIZAKI ◽  
H. SATOH ◽  
Y. SATO ◽  
S. NUKUI ◽  
M. SHIBASAKI ◽  
...  

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