Conformationally locked bicyclo[4.3.0]nonane carbanucleosides: synthesis and bio-evaluation

2014 ◽  
Vol 12 (46) ◽  
pp. 9439-9445 ◽  
Author(s):  
Tony K. M. Shing ◽  
Anthony W. H. Wong ◽  
Huiyan Li ◽  
Z. F. Liu ◽  
Paul K. S. Chan
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Wittig Olefination ◽  
Key Steps ◽  
Conformationally Locked

d-Ribose was converted into 3 novel carbobicyclic nucleosides bearing a bicyclo[4.3.0]nonane framework in 16–19 steps with 5–12% overall yields involving a Wittig olefination and an intramolecular Diels–Alder reaction as the key steps.

Exploratory synthetic investigations related to 12a-deoxypillaromycinone

2002 ◽  
Vol 80 (6) ◽  
pp. 728-738 ◽  
Author(s):  
Lan Wang ◽  
Sanath K Meegalla ◽  
Cheng-Lin Fang ◽  
Nicholas Taylor ◽  
Russell Rodrigo
Keyword(s):  
Double Bond ◽  
Catalytic Hydrogenation ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Step Procedure ◽  
Key Steps

Furfural is converted to suitably substituted AB synthon 21 for 12a-deoxypillaromycinone in 10 steps by a sequence involving the following key steps: intramolecular Diels-Alder reaction of a furan, 5-endo-trig cleavage of the oxabicyclo adducts 18, and catalytic hydrogenation of the double bond of a tetrasubstituted enone to produce 19. Enones 21a and 21b obtained by dehydrogenation of 19a and 19b, respectively, are then annulated with ethyl 2-methoxy-6-methylbenzoate in a four-step procedure to generate tetracyclic products 25 in 14 steps from furfural.

Ring-Closing Metathesis Approach to Cage Propellanes Containing Oxepane and Tetrahydrofuran Hybrid System

Synthesis ◽  
2017 ◽  
Vol 49 (24) ◽  
pp. 5339-5350 ◽  
Author(s):  
Sambasivarao Kotha ◽  
Subba Cheekatla ◽  
Darshan Mhatre
Keyword(s):  
Claisen Rearrangement ◽  
Alder Reaction ◽  
Diels Alder ◽  
Ring Closing Metathesis ◽  
Cage Compounds ◽  
Transannular Cyclization ◽  
Diels Alder Reaction ◽  
Grignard Addition ◽  
Key Steps ◽  
First Time

The preparation of a variety of structurally interesting oxygenated cage compounds involving atom-economic processes such as Claisen rearrangement, Diels–Alder reaction, [2+2] photocycloaddition, and ring-closing metathesis (RCM) as key steps is reported. For the first time, oxepane ring system is introduced in cage framework using olefin metathesis as a key step. These cage systems assembled here are difficult to prepare by traditional methods. The synthetic sequence described here opens up new routes to higher order polycycles containing heteroatoms without the involvement of protecting groups. Transannular cyclization observed during Grignard addition and the RCM protocol used here may be applicable to generate unknown oxygenated cage systems.

Protecting-Group-Free Total Synthesis of Anticancer (±)-Melotenine A

Synthesis ◽  
2021 ◽  
Author(s):  
Adisak Thanetchaiyakup ◽  
Hassayaporn Rattanarat ◽  
Sudaporn Aree ◽  
Tanwawan Duangthongyou ◽  
Tanin Nanok ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Human Cancer ◽  
Alder Reaction ◽  
Diels Alder ◽  
Protecting Groups ◽  
Protecting Group ◽  
Ring Closing Metathesis ◽  
Human Cancer Cell Lines ◽  
Diels Alder Reaction ◽  
Key Steps

Melotenine A, isolated from Melodinus tenuicaudatus, possesses significant anticancer activity against several human cancer cell lines. The synthesis of (±)-melotenine A was achieved without the use of any protecting groups in 11 steps with an overall yield of 7%. The key steps of our strategy were the Diels–Alder reaction to construct the tetracyclic framework and ring-closing metathesis to form the seven-membered ring of (±)-melotenine A.

Synthesis of Modified Phenylalanine Peptides by Cross Enyne Metathesis and a Diels-Alder Reaction as Key Steps

2012 ◽  
Vol 2012 (9) ◽  
pp. 1843-1850 ◽  
Author(s):  
Sambasivarao Kotha ◽  
Deepti Goyal née Bansal ◽  
Niranjan Thota ◽  
Venu Srinivas
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Enyne Metathesis ◽  
Diels Alder Reaction ◽  
Key Steps

Diels–Alder approach to (±)-longifolene: A formal synthesis

1992 ◽  
Vol 70 (5) ◽  
pp. 1375-1384 ◽  
Author(s):  
Tse-Lok Ho ◽  
Wen-Lung Yeh ◽  
John Yule ◽  
Hsing-Jang Liu
Keyword(s):  
Maleic Anhydride ◽  
Ring Expansion ◽  
Alder Reaction ◽  
Diels Alder ◽  
Formal Synthesis ◽  
Racemic Form ◽  
Diels Alder Reaction ◽  
Key Steps

A formal synthesis of longifolene in racemic form is concluded starting from the Diels–Alder reaction of 6,6-di-methylfulvene and maleic anhydride. Key steps are cyclodehydration, conjugate methylation, and ring expansion.

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