Cyclophanes. IV. Synthetic approaches to cyclophane dienes. The preparation of [2,2](2,7)Naphthalenophane-1,11-diene

1976 ◽  
Vol 29 (1) ◽  
pp. 163 ◽  
Author(s):  
JR Davy ◽  
JA Reiss
Keyword(s):  
Ring System ◽  
Ring Contraction ◽  
Stevens Rearrangement ◽  
Elimination Procedure ◽  
Synthetic Approaches ◽  
Hofmann Elimination

The synthesis of [2,2](2,7)naphthalenophane-1,ll-diene (2a) from 2,13-dithia[3,3](2,7)naphthalenophane (4) by means of a Stevens rearrangement ring contraction and a Hofmann elimination procedure is described. The diene was found to undergo an efficient oxidative photochemical cyclization to coronene. Several other reactions of the naphthalenophane ring system are described, and the stereochemistry of the macrocycle is discussed.

Cyclophanes. VI. The synthesis of [2,2](3,3')biphenylparacyclophanedienes

1976 ◽  
Vol 29 (6) ◽  
pp. 1267 ◽  
Author(s):  
PJ Jessup ◽  
JA Reiss
Keyword(s):  
Ring Opening ◽  
Ring System ◽  
Ring Contraction ◽  
Stevens Rearrangement ◽  
Ring Opening Reaction ◽  
Disubstituted Benzene ◽  
Contraction Procedure

The preparations of [2,2](3,3')biphenylparacyclophane-1,9-dine (19) and a dimethyl derivative (20) synthesized by a ring-contraction procedure of the corresponding dithiacyclophanes (11) and (12) are reported. Both dienes (19) and (20) photocyclized under oxidative conditions to the benzo[ghi]- perylenes (21) and (22). Difficulties associated with the Stevens rearrangement in cyclophanes containing a para-disubstituted benzene moiety have been rationalized in terms of a competing ring- opening reaction. Several other reactions of the biphenylparacylophane ring system are reported, and the stereochemistry of the macrocycle is discussed.

Diversity-Oriented Synthetic Approaches for Furoindoline: A Review

2019 ◽  
Vol 16 (3) ◽  
pp. 342-368 ◽  
Author(s):  
Ramandeep Kaur ◽  
Yagyesh Kapoor ◽  
Sundeep K. Manjal ◽  
Ravindra K. Rawal ◽  
Kapil Kumar
Keyword(s):  
Rheumatoid Arthritis ◽  
Cancer Cachexia ◽  
Biological Activities ◽  
Ring System ◽  
Synthetic Methods ◽  
Structural Units ◽  
Current Article ◽  
Tetrahydropyranyl Ether ◽  
Synthetic Approaches ◽  
Synthetic Target

The furo [2,3-b] indoline ring system is one of the most important structural units in various natural products. It has been known to have inherent biological activities and is utilized as a synthetic target for a number of natural compounds; therefore, this has contributed to a great demand for the growth of synthetic methods for this ring system. Most important compounds with furoindoline ring system are physovenine, madindoline A and B and makomotindoline etc. These compounds are well known to exhibit biological activity against different diseases such as glaucoma, cancer, cachexia, Castleman’s disease, rheumatoid arthritis, etc. The current article focuses on various synthetic approaches for furoindoline containing compounds and essential furoindoline moiety, such as oxindole-5-O-tetrahydropyranyl ether route etc., and various other diastereoand enantio- controlled approach in a very concise way.

Untersuchungen zur Ringkontraktion am 1,4-Dithia-2,6-diaza-3,5-diborinan-System/ Studies on Ring Contraction of the l,4-Dithia-2,6-diaza-3,5-diborinane System

1988 ◽  
Vol 43 (8) ◽  
pp. 959-962 ◽  
Author(s):  
Carl Habben ◽  
Anton Meiler ◽  
Stefan Pusch
Keyword(s):  
Mass Spectra ◽  
Ring System ◽  
Membered Ring ◽  
Ring Contraction ◽  
C Nmr

AbstractThe 1,4-dithia-2,6-diaza-3,5-diborinanes 1a-d react with elemental sodium with formation of the 1,3-diaza-2,4-diboretidines 2a-d. By use of more sodium in case of 1 d or 3,5-bis(diethylamino)- 2-cyclohexyl-6-trimethylsilyldiborinane, the 1,3-thiaza-2,4-diboretidines 3 were formed. 3.5-Dimethyl-2,6-bis(trimethylsilyl)-1,4-dithia-2,6-diaza-3,5-diborinane gives the borazine 4, The reaction of di-t-butyl-sulfurdiimide with 2,6-di-t-butyl-3,5-dimethyl-1,4-dithia-2,6-diaza-3,5-diborinane leads by ring contraction to the four-membered ring system 5. 1H, 11B, 13C NMR and mass spectra are reported and discussed.

Studies on the synthesis of the decahydro-as-indacene ring system of (-)-spinosyn A via transannular Diels-Alder reactions of substituted (E,E,E)-cyclododeca-1,6,8-trienes

2000 ◽  
Vol 78 (6) ◽  
pp. 757-771 ◽  
Author(s):  
Scott A Frank ◽  
Andrea B Works ◽  
William R Roush
Keyword(s):  
Transition State ◽  
Alder Reaction ◽  
Ring System ◽  
Diels Alder ◽  
Tandem Reactions ◽  
Ring Contraction ◽  
Diels Alder Reaction ◽  
Key Features ◽  
Stereoselective Syntheses

Stereoselective syntheses of decahydro-as-indacenes 31 and 54 are reported. The key features of our syntheses of 31 and 54 are the tandem Ireland-Claisen ring contraction of lactones 29 and 38 followed by the transannular Diels-Alder cyclization of cyclododecatrienes 30 and 35. Transition state modeling of both the transannular Diels-Alder reaction and the Ireland-Claisen ring contraction using PCModel is also described.Key words: transannular Diels-Alder reactions, tandem reactions, Claisen ring contraction, Spinosyn A, synthetic study.

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