Design, Prins-cyclization reaction promoting diastereoselective synthesis of 10 new tetrahydropyran derivatives and in vivo antinociceptive evaluations

2012 ◽  
Vol 58 ◽  
pp. 1-11 ◽  
Author(s):  
Saulo L. Capim ◽  
Paulo H.P. Carneiro ◽  
Paloma C. Castro ◽  
Maithê R.M. Barros ◽  
Bruno G. Marinho ◽  
...  
Keyword(s):  
Cyclization Reaction ◽  
Diastereoselective Synthesis ◽  
Prins Cyclization

Stereoselective synthesis of O-tosyl azabicyclic derivatives via aza Prins reaction of endocyclic N-acyliminium ions: application to the total synthesis of (±)-epi-indolizidine 167B and 209D

2014 ◽  
Vol 12 (36) ◽  
pp. 7026-7035 ◽  
Author(s):  
Anil K. Saikia ◽  
Kiran Indukuri ◽  
Jagadish Das
Keyword(s):  
Total Synthesis ◽  
Stereoselective Synthesis ◽  
Cyclization Reaction ◽  
Diastereoselective Synthesis ◽  
Prins Reaction ◽  
Prins Cyclization ◽  
Acyliminium Ions

A diastereoselective synthesis of 4-O-tosyl piperidine containing azabicyclic derivatives has been established via Prins cyclization reaction. This protocol has been applied for the total synthesis of (±)-epi-indolizidine 167B and 209D.

Diastereoselective Synthesis of Substituted Tetrahydrothiophenes and -thiopyrans via Thia-Prins Cyclization Reaction

2015 ◽  
Vol 80 (5) ◽  
pp. 2641-2648 ◽  
Author(s):  
Madhurjya Borah ◽  
Paramartha Gogoi ◽  
Kiran Indukuri ◽  
Anil K. Saikia
Keyword(s):  
Cyclization Reaction ◽  
Diastereoselective Synthesis ◽  
Prins Cyclization

ChemInform Abstract: Diastereoselective Synthesis of Substituted Tetrahydrothiophenes and -thiopyrans via Thia-Prins Cyclization Reaction.

ChemInform ◽  
2015 ◽  
Vol 46 (29) ◽  
pp. no-no
Author(s):  
Madhurjya Borah ◽  
Paramartha Gogoi ◽  
Kiran Indukuri ◽  
Anil K. Saikia
Keyword(s):  
Cyclization Reaction ◽  
Diastereoselective Synthesis ◽  
Prins Cyclization

Diastereoselective Synthesis of Substituted Tetrahydrofurans via Prins Cyclization of Enol Ethers

2014 ◽  
Vol 79 (18) ◽  
pp. 8592-8598 ◽  
Author(s):  
Paramartha Gogoi ◽  
Vijay K. Das ◽  
Anil K. Saikia
Keyword(s):  
Diastereoselective Synthesis ◽  
Prins Cyclization ◽  
Enol Ethers

scholarly journals Alternative pathways of zeaxanthin biosynthesis in a Flavobacterium species. Experiments with nicotine as inhibitor

1974 ◽  
Vol 144 (2) ◽  
pp. 231-243 ◽  
Author(s):  
J C B McDermott ◽  
D J Brown ◽  
G Britton ◽  
T W Goodwin
Keyword(s):  
Cyclization Reaction ◽  
Biosynthetic Pathways ◽  
Anaerobic Conditions ◽  
Anaerobic Process ◽  
Alternative Pathways ◽  
Nicotine Concentration ◽  
Β Carotene

In Flavobacterium R1519, nicotine blocks zeaxanthin biosynthesis by specifically inhibiting the cyclization reaction. Lycopene (at high nicotine concentrations, e.g. 7.5mm) and rubixanthin (at low nicotine concentration, e.g. 1mm) replace zeaxanthin as the main carotenoid. On removal of the nicotine lycopene is converted into β-carotene under anaerobic conditions and into zeaxanthin in the presence of O2. The conversion in vivo of β-carotene into zeaxanthin was also demonstrated. Cyclization (an anaerobic process) thus precedes hydroxylation (O2-requiring) in the biosynthesis of zeaxanthin. The conversion in vivo of rubixanthin into β-cryptoxanthin and into zeaxanthin was demonstrated, thus indicating the operation of alternative pathways of zeaxanthin biosynthesis. Several alternative biosynthetic pathways are considered and the results are also discussed in terms of reaction sequences of carotenoid ‘half-molecules’.

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