Preparation of 7-spiroepoxy and 7,7-disubstituted cephalosporanate 1,1-dioxide from 7-diazocephalosporanate 1,1-dioxide: Reactions of 7-diazocephalosporanate 1,1-dioxide with aldehydes

1991 ◽  
Vol 56 (11) ◽  
pp. 2352-2361 ◽  
Author(s):  
David Czajkowski ◽  
Oludotun A. Phillips ◽  
Narender A. V. Reddy ◽  
Paul Spevak ◽  
Bruce Lix ◽  
...  
Keyword(s):  
Boron Trifluoride ◽  
Boron Trifluoride Etherate ◽  
Tert Butyl ◽  
Profound Influence ◽  
Carbonyl Products

The reactions of tert-butyl-3-acetoxymethyl-3-cephem-7-diazocephalosporanate 1,1-dioxide (I) with acetaldehyde, benzaldehyde, 2-thiophene caboxaldehyde, 3-thiophene carboxaldehyde, 2-furan carboxaldehyde, 3-furan carboxaldehyde and isobutyraldehyde have been studied. Use of boron trifluoride etherate as a catalyst for these reactions was found to accelerate the reactions markedly and to favour the formation of aldehydes rather than the ketones at C-7 position as the carbonyl product. The products obtained from these reactions and the ratios of carbonyl products to epoxides suggest that the R groups of the carbonyl component have profound influence on the reactions.

Synthesis of optically active l-acyl-2-O-alkyl-sn-glycero-3-phosphocholine via 1-O-benzyl-sn-glycerol 3-arenesulfonate

1990 ◽  
Vol 68 (1) ◽  
pp. 360-365 ◽  
Author(s):  
Shaukat Ali ◽  
Robert Bittman
Keyword(s):  
Benzyl Alcohol ◽  
Alkyl Group ◽  
Boron Trifluoride ◽  
Enantiomeric Excess ◽  
Boron Trifluoride Etherate ◽  
Optically Active ◽  
Epoxide Ring ◽  
Phospholipid Synthesis ◽  
Tert Butyl ◽  
Very High

A stereocontrolled route to 1-palmitoyl-2-O-hexadecyl-sn-glycero-3-phosphocholine from (R)-glycidyl tosylate is described. This method gives very high enantioselectivity (93–96% enantiomeric excess) and can be used to prepare 3-acyl-2-O-alkyl-sn-glycero-1-phosphocholines from (S)-glycidyl tosylate. The key step is the preparation of 1-O-benzyl-sn-glycerol 3-tosylate by the boron trifluoride etherate catalyzed regio- and stereo-specific opening of the epoxide ring with excess benzyl alcohol. The alkyl group is introduced using alkyl trifluoromethanesulfonate in the presence of excess 2,6-di-tert-butyl-4-methylpyridine. Debenzylation gives 2-O-alkyl-sn-glycerol 3-arenesulfonate, which is acylated and then converted into the phosphocholine. The use of chiral glycidyl derivatives as starting materials for the synthesis of glycerophospholipids is discussed.Key words: acylalkylglycerophospholipids, phospholipid synthesis, glycidyl derivatives in phospholipid synthesis, epoxides as precursors of phospholipids.

Synthesis of o-isopentenylphenols

1971 ◽  
Vol 24 (11) ◽  
pp. 2355 ◽  
Author(s):  
J Hlubucek ◽  
E Ritchie ◽  
WC Taylor
Keyword(s):  
Phosphoric Acid ◽  
Zinc Chloride ◽  
Boron Trifluoride ◽  
Boron Trifluoride Etherate ◽  
Stannic Chloride ◽  
Counter Ion

The effect of the solvent and the counter-ion on the ring alkylation of 3- and 4-methoxyphenols by isopentenyl bromide has been examined. Under strictly anhydrous conditions good and consistent yields of the o- isopentenylphenols were obtained with the combination potassium- toluene, but sodium-toluene was more convenient. ��� Boron trifluoride etherate was more satisfactory than stannic chloride, zinc chloride, or phosphoric acid in catalysing the condensation of 3- and 4-methoxy-phenols with 2-methylbut-3-en-2-ol to the corresponding o-isopentenylphenols. Aryl α,α-dimethylpropargyl ethers were partially hydrogenated to the corresponding α,α- dimethylallyl ethers which rearranged in boiling N,N-diethyl-aniline to o-isopentenylphenols in high overall yield.

scholarly journals Synthesis of 5,6,7,8-Tetrahydroquinolines by Thermolysis of Oxime O-Allyl Ethers in the Presence of Boron Trifluoride Etherate.

1993 ◽  
Vol 41 (7) ◽  
pp. 1297-1298 ◽  
Author(s):  
Junko KOYAMA ◽  
Tamaki OGURA ◽  
Kiyoshi TAGAHARA ◽  
Masaaki MIYASHITA ◽  
Hiroshi IRIE
Keyword(s):  
Boron Trifluoride ◽  
Boron Trifluoride Etherate ◽  
Allyl Ethers

Syntheses of the alkali metal borodeuterides

1967 ◽  
Vol 45 (21) ◽  
pp. 2583-2588 ◽  
Author(s):  
J. G. Atkinson ◽  
D. W. MacDonald ◽  
R. S. Stuart ◽  
P. H. Tremaine
Keyword(s):  
Sodium Methoxide ◽  
Boron Trifluoride ◽  
Deuterium Oxide ◽  
Secondary Alcohol ◽  
Boron Trifluoride Etherate ◽  
Residual Hydrogen ◽  
Lithium Deuteride ◽  
Chemical Purity ◽  
Molar Scale ◽  
Sodium Borodeuteride

A synthesis of sodium borodeuteride on a molar scale has been developed. Trimethylamineborane was exchanged (6) with deuteriosulfuric acid in deuterium oxide to obtain trimethylamineborane-d3 of a high isotopic purity. Reaction of trimethylamineborane-d3 with sodium methoxide in diglyme at 120–150 °C yielded sodium borodeuteride, which, after purification, was obtained in a 40–50% overall yield. The conditions for obtaining material of a high isotopic and chemical purity were found to be rather stringent but, once worked out, were easily reproducible.Lithium borodeuteride and potassium borodeuteride were also prepared from trimethylamineborane-d3 and the corresponding methoxide salts. An alternative synthesis of lithium borodeuteride, involving the reaction between lithium deuteride and boron trifluoride etherate, was found to be more satisfactory, since it avoided the formation of stable 1:1 solvent complexes with lithium borodeuteride.The products that were obtained had a chemical purity of 97%, and contained 98–99 atom % deuterium. The deuterium analyses were performed by reducing a series of ketones containing no α hydrogens and analyzing the secondary alcohol by nuclear magnetic resonance for residual hydrogen on the alcohol carbon.

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