Stereoselective total synthesis of (±)-isocostic and (±)-3-oxoisocostic acids

1982 ◽  
Vol 35 (2) ◽  
pp. 451 ◽  
Author(s):  
R Cruz ◽  
RM Martinez
Keyword(s):  
Total Synthesis ◽  
Trans Isomer ◽  
Michael Addition ◽  
Potassium Salt

Stereoselective total synthesis of the title compounds, two new sesquiterpenes isolated from a Mexican plant, are described. The key step in the synthesis is based on classical santon in syntheses by the stereoselective Michael addition of the potassium salt of ethyl α-cyanoacetate to the dienone(4), to give the cis adduct (5), in an 8 : 2 ratio with the trans isomer. Further appropriate transformation of this cis adduct (5) leads to formation of either isocostic acid (1) or 3-oxoisocostic acid (2).

scholarly journals Towards the total synthesis of keramaphidin B

2016 ◽  
Vol 12 ◽  
pp. 1096-1100 ◽  
Author(s):  
Pavol Jakubec ◽  
Alistair J M Farley ◽  
Darren J Dixon
Keyword(s):  
Total Synthesis ◽  
Michael Addition ◽  
Synthetic Strategy

The enantio- and diastereoselective Michael addition of a δ-valerolactone-derived pronucleophile to a substituted furanyl nitroolefin catalysed by a bifunctional cinchonine-derived thiourea has been used as the key stereocontrolling step in a new synthetic strategy to the heavily functionalised piperidine core of keramaphidin B.

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.

Total Synthesis of (−)-Kainic Acid via Intramolecular Michael Addition: A Second-Generation Route

2008 ◽  
Vol 10 (9) ◽  
pp. 1711-1714 ◽  
Author(s):  
Hiroshi Sakaguchi ◽  
Hidetoshi Tokuyama ◽  
Tohru Fukuyama
Keyword(s):  
Total Synthesis ◽  
Kainic Acid ◽  
Michael Addition ◽  
Second Generation

Intramolecular Michael Addition of N- and O-Centred Nucleophiles to Tethered Acrylates. The Role of Double-Bond Geometry in Controlling the Diastereo- selectivity of Cyclizations Leading to 2,6-Disubstituted Tetrahydropyrans and Piperidines.

1998 ◽  
Vol 51 (1) ◽  
pp. 9 ◽  
Author(s):  
Martin G. Banwell ◽  
Brett D. Bissett ◽  
Chinh T. Bui ◽  
Ha T. T. Pham ◽  
Gregory W. Simpson
Keyword(s):  
Double Bond ◽  
Total Synthesis ◽  
Michael Addition ◽  
Reductive Amination ◽  
Major Product ◽  
Enantioselective Synthesis ◽  
Cyclization Reactions ◽  
Glandular Secretion

The oxyanion derived from hydroxyacrylate E-(5) undergoes smooth intramolecular Michael addition to give the trans-2,6-disubstituted tetrahydropyran (7) as the major product of reaction. In contrast, the oxyanion obtained from isomer Z-(5) cyclizes to give the cis-2,6-disubstituted tetrahydropyran (6) as the major product. Such chemistry has been extended to the enantioselective synthesis of (+)-(6) the acquisition of which constitutes a formal total synthesis of acid (+)-(2), a constituent of the glandular secretion from the civet cat (Viverra civetta). Reductive amination of keto acrylate (12) affords an intermediate amine which cyclizes, in situ, to give the cis-2,6-disubstituted piperidine (26). Analogous treatment of compound (13) delivers the isomeric trans-2,6-disubstituted piperidine (27) as the exclusive product of reaction. Transition state structures have been proposed to account for the diastereoselectivities observed in all of the cyclization reactions.

The Total Synthesis of Spermine Alkaloid Kukoamine Bimesylate

Synlett ◽  
2018 ◽  
Vol 29 (20) ◽  
pp. 2669-2672
Author(s):  
Kai Dong
Keyword(s):  
Total Synthesis ◽  
Michael Addition ◽  
Addition Reaction ◽  
Cyano Group ◽  
Michael Addition Reaction ◽  
Amino Groups ◽  
Competitive Reaction ◽  
12 Steps ◽  
Cyano Groups

The first total synthesis of kukoamine B bimesylate was completed from 1,4-diaminobutane dihydrochloride in 12 steps with a 11.4% overall yield, and all the steps could be carried out at a kilogram scale. The cyano groups were used as the precursor of amino groups to avoid the competitive reaction delicately. The aza-Michael addition reaction, amidation and hydrogenation of the cyano group sequence was streamlined as a general approach towards the synthesis of polyamine structures.

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