ChemInform Abstract: STUDIES ON THE TOTAL SYNTHESIS OF (2R, 4′R, 8′R)-α-TOCOPHEROL (VITAMIN E). STEREOSPECIFIC CYCLIZATIONS LEADING TO OPTICALLY ACTIVE CHROMANS

1981 ◽  
Vol 12 (45) ◽  
Author(s):  
N. COHEN ◽  
R. J. LOPRESTI ◽  
C. NEUKOM
Keyword(s):  
Vitamin E ◽  
Total Synthesis ◽  
Optically Active

Synthesis of Optically Active Hydroxyalkyl Cycloheptatrienes: A Key Step in the Total Synthesis of 6,11-Methylene-LXB4

Synlett ◽  
2020 ◽  
Vol 32 (01) ◽  
pp. 45-50
Author(s):  
Udo Nubbemeyer ◽  
Analuisa Nava ◽  
Lukas Trippe ◽  
Andrea Frank ◽  
Lars Andernach ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Total Synthesis ◽  
Structure Elucidation ◽  
Butyl Ester ◽  
Optically Active ◽  
Chiral Hplc ◽  
Reaction Conditions ◽  
Acid Product ◽  
Tert Butyl ◽  
Nabh4 Reduction

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.

ChemInform Abstract: Total Synthesis of Natural (+)-FR900482. Part 2. Efficient Syntheses of the Aromatic and the Optically Active Aliphatic Fragments.

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

ChemInform Abstract: Palladium-Mediated Asymmetric Synthesis of cis-3,6-Disubstituted Cyclohexenes. A Short Total Synthesis of Optically Active (+)-γ- Lycorane.

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