A practical and enantioselective synthesis of glycosphingolipids and related compounds. Total synthesis of globotriaosylceramide (Gb3)

1988 ◽  
Vol 110 (23) ◽  
pp. 7910-7912 ◽  
Author(s):  
K. C. Nicolaou ◽  
T. Caulfield ◽  
H. Kataoka ◽  
T. Kumazawa
Keyword(s):  
Total Synthesis ◽  
Enantioselective Synthesis ◽  
Related Compounds

Total Synthesis ofdl-Ascofuranone and Related Compounds

1995 ◽  
Vol 68 (9) ◽  
pp. 2727-2734 ◽  
Author(s):  
Hiroyuki Saimoto ◽  
Shin-ichiro Ohrai ◽  
Hitoshi Sashiwa ◽  
Yoshihiro Shigemasa ◽  
Tamejiro Hiyama
Keyword(s):  
Total Synthesis ◽  
Related Compounds

Studies Directed Towards the Total Synthesis of Anticapsin and Related Compounds. IV. Competitive Reaction of Amino and Carboxy Substituents in the Halohydrination of 2-Aminobicyclo[2.2.2]oct-5-ene-2-carboxylic Acid Derivatives

1994 ◽  
Vol 47 (12) ◽  
pp. 2221 ◽  
Author(s):  
MJ Crossley ◽  
SR Davies ◽  
TW Hambley
Keyword(s):  
Total Synthesis ◽  
The Other ◽  
X Ray Diffraction ◽  
Amino Groups ◽  
Competitive Reaction ◽  
Trimethylsilyl Group ◽  
X Ray ◽  
Tricyclic Compounds ◽  
Tricyclic Compound ◽  
Related Compounds

Bromohydrination of benzyl (1RS,2SR,4SR)-2-benzyloxycarbonylamino-1-trimethylsilyloxy-bicyclo[2.2.2]oct-5-ene-2-carboxylate (6a) and the (1RS,2RS,4SR)- diastereomer (6b) with N- bromoacetamide in aqueous dioxan has been investigated. These reactions are highly regio-and stereo-selective and give the corresponding bromohydrins (9a) and (9b), but in moderate to low yield. These bromohydrins have the necessary stereochemistry for conversion into anticapsin. The other products from the reaction are tricyclic compounds formed by capture of the anti- bromonium cation intermediates or resultant bromohydrins by interaction with the proximal protected carboxy and amino groups within the molecules. Thus the carbolactone (11) is formed from the endo -adduct (6a), and the carbonimidic acid derivative (12) and the cyclic urethane (13) are formed from the exo-adduct (6b). Cleavage of the trimethylsilyl group from the tricyclic compound (12) gives benzyl (1RS,2RS,3RS,7RS,8RS)-5-benzyloxy-2-bromo-8-hydroxy-4-oxa-6-azatricyclo[5.3.1.03,8]undec-5-ene-7-carboxylate(14), the structure of which was determined by X-ray diffraction methods and refined to a residual of 0.035 for 1549 independent observed reflections. The crystals of (14) are monoclinic, P21/c, a 12.954(3), b 6.197(3), c 26.784(7) Ǻ, β 95.33(2)°, Z 4. Reactions attempting to generate iodohydrins from the alkenes (6) were also highly regioselective and gave detrimethylsilylated iodo analogues of (11) and (13).

Total synthesis of novel conduritol related compounds capable of modulating insulin release.

1994 ◽  
Vol 4 (19) ◽  
pp. 2307-2312 ◽  
Author(s):  
D.C. Billington ◽  
F. Perron-Sierra ◽  
I. Picard ◽  
S. Beaubras ◽  
J. Duhault ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Insulin Release ◽  
Related Compounds

scholarly journals A concise enantioselective synthesis of the guaiane sesquiterpene (−)-oxyphyllol

2013 ◽  
Vol 9 ◽  
pp. 2028-2032 ◽  
Author(s):  
Martin Zahel ◽  
Peter Metz
Keyword(s):  
Total Synthesis ◽  
Enantioselective Synthesis ◽  
Englerin A ◽  
Epoxide Opening

(−)-Oxyphyllol was prepared in only 4 steps from an epoxy enone that already served as an intermediate for the total synthesis of the anticancer guaiane (−)-englerin A. A regio- and diastereoselective Co(II)-catalyzed hydration of the olefin and a transannular epoxide opening were used as the key reactions.

Synthesis of 14-hydroxy steroids. Total synthesis of methyl 14β-hydroxy-1,7,17-trioxo-5β,8-androstene-10β-oate and related compounds

1990 ◽  
Vol 68 (11) ◽  
pp. 1917-1922 ◽  
Author(s):  
Réjean Ruel ◽  
Pierre Deslongchamps
Keyword(s):  
Total Synthesis ◽  
Ammonium Salt ◽  
Michael Addition ◽  
Title Compound ◽  
Steroid Synthesis ◽  
Related Compounds ◽  
Acetylenic Ketone

The total synthesis of the title compound 22 and methyl 14α-hydroxy-5β,13α,8-androstene-1,7,17-trioxo-10β-oate 21 isomer is reported. We also describe the 1,6-Michael addition of 2-methyl-1,3-cyclopentanedione on dienone 14 and the protic ammonium salt catalyzed intramolecular Michael addition of cyclic β-ketoester on the conjugated acetylenic ketone 13. Keywords: cardenolides, steroid synthesis, aldol, Michael addition.

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