Enolic Ortho Esters. IV. Synthesis of the 8-α and 8-β Epimers of a 6-Oxa Steroidal Enolic Ortho Ester

1989 ◽  
Vol 42 (10) ◽  
pp. 1769 ◽  
Author(s):  
DJ Collins ◽  
AG Jhingran ◽  
SB Rutschmann
Keyword(s):  
Ethylene Oxide ◽  
Ethylene Glycol ◽  
Boron Trifluoride ◽  
Methanesulfonic Acid ◽  
Boron Trifluoride Etherate ◽  
Ortho Ester ◽  
Birch Reduction ◽  
Ortho Esters

Reaction of resorcinol (9) with methyl 1β-hydroxy-7aβ-methyl-5-oxo-2,3,3 a α,4,5,6,7,7a- octahydro-1H-indene-4α-carboxylate (10a) or with the corresponding 1,5-dioxo ester (15) in methanesulfonic acid gave ( �)-3,17 β-dihydroxy-6-oxaestra-l,3,5(10),8(9)-tetraen-7-one (11a) (98%), or (c)-3-hydroxy-6-oxaestra-1,3,5(10),8(9)-tetraene-7,17-dione (14) (91%), respectively. 3-O-Methylation of the phenolic keto lactone (14) followed by reaction with ethylene glycol gave (�)-17,17-ethylenedioxy-3-methoxy-6-oxaestra-1,3,5(10),8(9)- tetrae n-7-one (16). Reduction of this with lithium/ammonia afforded 77% of (�) 17,17-ethylenedioxy-3-methoxy-6-oxa-8 α-estra-1,3,5(10)-trien-7-one (71, which upon base-catalysed epimerization yielded 84% of the 8 β-epimer (19). Reaction of the 8 α-H lactone (17) or its 8 β- epimer (19) with ethylene oxide in the presence of boron trifluoride etherate yielded the corresponding phenolic ortho esters (�)-7,7:17,17-bis( ethylenedioxy )-3-methoxy-6-oxa-8 α-estra-1,3,S(10)- triene (23), and its 8 β- epimer (25), in 36 and 42% yields, respectively. Birch reduction of (23) and (25) afforded the corresponding enolic ortho ester ( �)-7,7:17,17-bis( ethylenedioxy )-3-methoxy-6-oxa-8 α-estra-2,5(10)- diene (26), and its 8 β-epimer (6), in 82 and 64% yields, respectively. Some related chemistry is described. The enolic ortho esters (26) and (6) were relatively inert to attack by methylmagne sium iodide under normal conditions.

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).

Digitoxigenin-3-alkyl ethers

1981 ◽  
Vol 59 (7) ◽  
pp. 1025-1027 ◽  
Author(s):  
Robert Greenhouse ◽  
Joseph M. Muchowski
Keyword(s):  
Ethylene Glycol ◽  
Boron Trifluoride ◽  
Boron Trifluoride Etherate ◽  
Alcoholic Medium ◽  
The Third ◽  
Alkyl Ethers

The synthesis of the title compounds was accomplished by (i) boron trifluoride etherate catalysed alkylation of digitoxigenin with diazoalkanes, (ii) silver tetrafluoroborate assisted solvolysis of 3-desoxy-3α-iododigitoxigen 2d in an alcoholic medium, and (iii) m-chloroperbenzoic acid induced oxidative solvolytic displacement on the iodo compound 2d in the presence of alcohols. The third process was the most useful for the preparation of the mono ethers 2e and 2f of ethylene glycol and glycerol, respectively.

STEROIDS AND RELATED PRODUCTS: XIX. THE SYNTHESIS OF 3,9,12,20-TETRAOXYGENATED 9,12-seco STEROIDS. PART III. 11-AZA STEROIDS. PART I

1962 ◽  
Vol 40 (11) ◽  
pp. 2153-2162 ◽  
Author(s):  
Ch. R. Engel ◽  
S. Rakhit
Keyword(s):  
Methyl Ester ◽  
Ethylene Glycol ◽  
Ethyl Acetate ◽  
Good Yield ◽  
Boron Trifluoride ◽  
Osmium Tetroxide ◽  
Periodic Acid ◽  
Boron Trifluoride Etherate ◽  
The Other ◽  
Other Hand

The smooth conversion of 3β-acetoxy-5α-pregnane-12,20-dione (IV), readily available from hecogenin (I), to Δ9(11)-3β,20β-diacetoxy-5α-pregnan-12-one (VIII) is reported. Ozonolysis of this product in ethyl acetate gave, in almost 90% yield, 3β-hydroxy-20β-acetoxy-9-oxo-9,12-seco-11-nor-5α-pregnan-12-oic acid (XI), further characterized by its ester derivatives XIa and XIb. The conversion of the seco acid XI to Δ8(9)-3β-hydroxy-20β-acetoxy-9-amino-9,12-seco-11-nor-5α-pregnen-12-oic acid lactam (12 → 9) (XII) and thence to Δ8(9)-N-acetyl-3β,20β-diacetoxy-11-aza-5α-pregnene (XIVa), the first 11-aza steroids to be known, is described. On the other hand, Δ9(11)-3β,20β-diacetoxy-5α-pregnen-12-one (VIII) is readily transformed to the 9α,11α-glycol VII with osmium tetroxide and thence, with periodic acid, to 3β,9α-dihydroxy-20β-acetoxy-11-oxo-11,12-seco-5α-pregnan-12-oic acid (X), characterized as the methyl ester Xa and diacetoxy methyl ester Xb, and easily converted to the acetoxy hydroxy keto dicarboxylic seco acid XIII. In the course of this work it is shown that, whereas ketalization of the saturated 12,20-diketone IV with ethylene glycol and boron trifluoride etherate gives a good yield of the 12-monoketal (in accordance with the reports of the literature), treatment of the analogous 16-unsaturated 12,20-diketone with the same reagents under the same conditions leads not to ketal formation but to addition of ethylene glycol in position 16.

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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