C,C-Double Bond Participation in the Acid-Catalyzed Cyclization of 9exo-Methyl-anti10,11-tricyclo[4.2.1.12,5]deca-3,7-diene-9endo, 10endo-diol. Influence of Steric Compression on the Product Distribution

1983 ◽  
Vol 66 (3) ◽  
pp. 914-920 ◽  
Author(s):  
Gerardo M. Ramos Tombo ◽  
Sarmistha Chakrabarti ◽  
Camille Ganter
Keyword(s):  
Double Bond ◽  
Product Distribution ◽  
Acid Catalyzed

scholarly journals Structure Determination of Two New Monocillin I Derivatives

2010 ◽  
Vol 5 (5) ◽  
pp. 1934578X1000500
Author(s):  
Jixun Zhan ◽  
E. M. Kithsiri Wijeratne ◽  
A. A. Leslie Gunatilaka
Keyword(s):  
Double Bond ◽  
Acid Solution ◽  
Beauveria Bassiana ◽  
Structure Determination ◽  
Spectroscopic Data ◽  
Enzymatic Process ◽  
Acid Catalyzed ◽  
Hydrolysis Of

Biotransformation of monocillin I (1) by Beauveria bassiana ATCC 7159 was investigated. Two new derivatives 2 and 3 were isolated and identified on the basis of the spectroscopic data. Compounds 2 and 3 are synthesized by hydration at 10,11-double bond and hydrolysis of 14,15-epoxide, respectively. The R configuration of 11-OH in 2 was established by the modified 2-methoxy-2-trifluoromethylphenylacetic acid (MTPA) method. The conversion of 1 to 2 and 3 was reconstituted in an acid solution, indicating that the formation of 2 and 3 is an acid-catalyzed instead of an enzymatic process.

Stereodivergent synthesis of 1,4-dicarbonyls by traceless charge–accelerated sulfonium rearrangement

Science ◽  
2018 ◽  
Vol 361 (6403) ◽  
pp. 664-667 ◽  
Author(s):  
Dainis Kaldre ◽  
Immo Klose ◽  
Nuno Maulide
Keyword(s):  
Natural Products ◽  
Double Bond ◽  
Carbonyl Group ◽  
Organic Synthesis ◽  
Relative Configuration ◽  
Chiral Induction ◽  
Tremendous Importance ◽  
Acid Catalyzed ◽  
Quaternary Stereocenters ◽  
Drug Scaffolds

The chemistry of the carbonyl group is essential to modern organic synthesis. The preparation of substituted, enantioenriched 1,3- or 1,5-dicarbonyls is well developed, as their disconnection naturally follows from the intrinsic polarity of the carbonyl group. By contrast, a general enantioselective access to quaternary stereocenters in acyclic 1,4-dicarbonyl systems remains an unresolved problem, despite the tremendous importance of 2,3-substituted 1,4-dicarbonyl motifs in natural products and drug scaffolds. Here we present a broad enantioselective and stereodivergent strategy to access acyclic, polysubstituted 1,4-dicarbonyls via acid-catalyzed [3,3]-sulfonium rearrangement starting from vinyl sulfoxides and ynamides. The stereochemistry at sulfur governs the absolute sense of chiral induction, whereas the double bond geometry dictates the relative configuration of the final products.

Development of a Hydrazine-Catalyzed Carbonyl-Olefin Metathesis Reaction

Synlett ◽  
2019 ◽  
Vol 30 (17) ◽  
pp. 1954-1965 ◽  
Author(s):  
Tristan H. Lambert
Keyword(s):  
Double Bond ◽  
Organic Synthesis ◽  
Olefin Metathesis ◽  
Type I ◽  
Type Ii ◽  
Metathesis Reaction ◽  
Alternative Strategies ◽  
Potential Applications ◽  
Acid Catalyzed ◽  
New Strategies

Carbonyl-olefin metathesis is a potentially powerful yet underexplored reaction in organic synthesis. In recent years, however, this situation has begun to change, most notably with the introduction of several different catalytic technologies. The development of one of those new strategies, based on hydrazine catalysts and a novel [3+2] paradigm for double bond metathesis, is discussed herein. First, the stage is set with a description of some potential applications of carbonyl-olefin metathesis and a discussion of alternative strategies for this intriguing reaction.1 Introduction2 Potential Applications of Carbonyl-Olefin Metathesis3 Carbonyl-Olefin Metathesis Strategies4 Direct (Type I): Non-Catalytic5 Direct (Type I): Acid-Catalyzed6 Indirect (Type II): Metal Alkylidenes7 Indirect (Type III): Hydrazine-Catalyzed8 Conclusion

The Reaction of 5-Substituted-2-Norbornenes with Phenylselenyl Chloride

2008 ◽  
Vol 61 (4) ◽  
pp. 283 ◽  
Author(s):  
D. Alan R. Happer ◽  
Thomas Francis ◽  
Jonathan M. White
Keyword(s):  
Double Bond ◽  
Product Distribution ◽  
Major Product ◽  
Factors Influencing

In dichloromethane, 5-substituted-2-norbornenes add phenylselenyl chloride across the double bond to give adducts in which the phenylselanyl substituent is exo and the chloro endo. The relative yields of the two regioisomeric adducts are reported for several of these. For most, the formation of the 2-chloro-3-phenyselanyl adduct is favoured. The main exceptions are when the 5-substituent is exo and a good resonance donor, where the 3-chloro-2-phenylselanyl adduct is the major product. Possible factors influencing the product distribution are discussed.

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