Oxidative Hydrolysis of 1,3-Dithiane Derivatives to Carbonyl Compounds Using Lead Dioxide/Boron Trifluoride Etherate Reagents

Synthesis ◽  
1982 ◽  
Vol 1982 (07) ◽  
pp. 580-582 ◽  
Author(s):  
Dario Ghiringhelli
Keyword(s):  
Carbonyl Compounds ◽  
Boron Trifluoride ◽  
Lead Dioxide ◽  
Boron Trifluoride Etherate ◽  
Hydrolysis Of

Enolic Ortho Esters. I. Preparation and Birch Reduction of Some Coumarinoid Ortho Esters

1989 ◽  
Vol 42 (8) ◽  
pp. 1235 ◽  
Author(s):  
DJ Collins ◽  
LM Downes ◽  
AG Jhingran ◽  
SB Rutschmann ◽  
GJ Sharp
Keyword(s):  
Carbon Tetrachloride ◽  
Acid Hydrolysis ◽  
Boron Trifluoride ◽  
Boron Trifluoride Etherate ◽  
High Yield ◽  
Ortho Ester ◽  
Birch Reduction ◽  
High Yields ◽  
Ortho Esters ◽  
Hydrolysis Of

Phenolic ortho esters such as 4′,4′-dimethylspiro[2H-1-benzopyran-2,2′-[1,3]dioxolan] (7b) and 4′,4′-dimethyl-3,4-dihydrospiro[2H-1-benzopyran-2,2′-[1,3]dioxolan] (9c) were prepared in low yields by reaction of 2H-1-benzopyran-2-one (5) or 3,4-dihydro-2H-1-benzopyran-2-one (8a) with 2,2-dimethyloxiran in carbon tetrachloride in the presence of boron trifluoride etherate. 3,4-Dihydrospiro[2H-1-benzopyran-2,2′-[1,3] dioxoan ] (9a) and the corresponding 7-methoxy compound (9e) were obtained in high yield by reaction of (8a) or its 7-methoxy analogue (8b) with 1,2-bis(trimethylsily1oxy)ethane (10) in the presence of trimethylsilyl trifluoromethane-sulfonate . Birch reduction of phenolic ortho esters such as (9c) and (9e) afforded the enolic ortho esters 4′,4′-dimethyl-3,4,5,8-tetrahydrospiro[2H-1-benzopyran-2,2′-[1,3] dioxola n] (11a) and 7-methoxy-3,4,5,8-tetrahydrospiro[2H-1-benzopyran-2,2′-[1,3]dioxolan] (llc) in high yields. Birch reduction of 4′,4′,5′,5′-tetramethylspiro[2H-1-benzopyran-2,2′-[1,3]dioxolan] (7c) gave a 1 : 3 mixture of 4′,4′,5′,5′-tetramethyl-3,4-dihydrospiro[2H-1-benzopyran-2,2′-[l,3] dioxolan ] (9d) and the corresponding 3,4,5,8-tetrahydro compound (11b). Acid hydrolysis of the enolic ortho ester (11a) gave 67% of 2-hydroxy-2-methylpropyl 3-(2-oxocyclohex-3-enyl) propanoate (20).

Neuroleptic 2-chloro-11-(2-piperazineethoxy)-10,11-dihydrodibenzo[b,f]thiepins: Synthesis and pharmacology

1984 ◽  
Vol 49 (8) ◽  
pp. 1810-1815 ◽  
Author(s):  
Václav Bártl ◽  
Jiří Jílek ◽  
Jiřina Metyšová ◽  
Martin Valchář ◽  
Antonín Dlabač ◽  
...  
Keyword(s):  
Alkaline Hydrolysis ◽  
Boron Trifluoride ◽  
Boron Trifluoride Etherate ◽  
Dopamine Metabolism ◽  
Substitution Reactions ◽  
Activity Profile ◽  
Hydrolysis Of ◽  
Brain Striatum ◽  
Hydroxyethyl Piperazine ◽  
Central Depressant

A reaction of 8-chloro-10,11-dihydrodibenzo[b,f]thiepin-10-ol with 2-bromoethanol and boron trifluoride etherate produced the 2-bromoethyl ether II which was subjected to substitution reactions with 1-methylpiperazine, 1-(2-hydroxyethyl)piperazine, 1-(3-hydroxypropyl)piperazine and 1-ethoxycarbonylpiperazine to give the title piperazinoethoxy compounds IV-VII. Alkaline hydrolysis of the carbamate VII afforded the monosubstituted piperazine VIII. Compounds IV-VI are neuroleptics with an interesting activity profile: they are little toxic, have strong central depressant and antimorphine activity, mild cataleptic effects, they intensively increase the dopamine metabolism in the rat brain striatum and are almost free of the peripheral adrenolytic efficacy.

Aminocyclitols. III. Synthesis of diaminocyclohexanediols

1979 ◽  
Vol 57 (14) ◽  
pp. 1870-1876 ◽  
Author(s):  
Gerry Kavadias ◽  
Robert Droghini
Keyword(s):  
Thionyl Chloride ◽  
Sodium Azide ◽  
Ring Opening ◽  
Boron Trifluoride ◽  
Boron Trifluoride Etherate ◽  
Reaction Sequence ◽  
Acidic Hydrolysis ◽  
Ring Opening Reactions ◽  
Cis And Trans ◽  
Hydrolysis Of

Reaction of N,N′-diethoxycarbonyl-2,5-dideoxystreptamine (1b) with thionyl chloride produced the iminoether dihydrochloride 8 which, upon simple treatment with water gave the di-N,O-carbonyl compound 9. Acidic hydrolysis of 9 yielded the aminocyclitol 2a. Alternatively, 2a was prepared from N,N′-dibenzoyl-2,5-dideoxystreptamine (1c) via the oxazoline 10 followed by acidic hydrolysis. Treatment of 1c with triethyl orthoacetate in the presence of boron trifluoride etherate produced the oxazoline 11 and the latter product was hydrolyzed to give 3a. By the same reaction sequence, 1e and 1h were converted to the oxazolines 12 and 13 which upon acidic hydrolysis provided the enantiomeric aminocyclitols 4 and 5. Ring-opening reactions of cis- and trans-1,4-diepoxycyclohexanes (14 and 16) with sodium azide to the diazido compounds 15 and 17, followed by reduction, afforded the aminocyclitols 6 and 7.

A FACILE SYNTHESIS AND REACTIONS OF AMINO SELENOLO[2,3-b]PYRIDINE CARBOXYLATE

2015 ◽  
Vol 12 (1) ◽  
pp. 3910-3918 ◽  
Author(s):  
Dr Remon M Zaki ◽  
Prof Adel M. Kamal El-Dean ◽  
Dr Nermin A Marzouk ◽  
Prof Jehan A Micky ◽  
Mrs Rasha H Ahmed
Keyword(s):  
Biological Activity ◽  
Carbonyl Compounds ◽  
Mass Spectra ◽  
The Other ◽  
Pyridine Derivatives ◽  
Facile Synthesis ◽  
High Biological Activity ◽  
Basic Hydrolysis ◽  
Pyridine Carboxylate ◽  
Hydrolysis Of

 Incorporating selenium metal bonded to the pyridine nucleus was achieved by the reaction of selenium metal with 2-chloropyridine carbonitrile 1 in the presence of sodium borohydride as reducing agent. The resulting non isolated selanyl sodium salt was subjected to react with various α-halogenated carbonyl compounds to afford the selenyl pyridine derivatives 3a-f  which compounds 3a-d underwent Thorpe-Ziegler cyclization to give 1-amino-2-substitutedselenolo[2,3-b]pyridine compounds 4a-d, while the other compounds 3e,f failed to be cyclized. Basic hydrolysis of amino selenolo[2,3-b]pyridine carboxylate 4a followed by decarboxylation furnished the corresponding amino selenolopyridine compound 6 which was used as a versatile precursor for synthesis of other heterocyclic compound 7-16. All the newly synthesized compounds were established by elemental and spectral analysis (IR, 1H NMR) in addition to mass spectra for some of them hoping these compounds afforded high biological activity.

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