NOVEL MIGRATION OF METHYL GROUP OF 6,10,10-TRIMETHYL-4-OXOTRICYCLO[4.4.0.01,3]DECANE WITH BORON TRIFLUORIDE IN ACETIC ACID-ACETIC ANHYDRIDE

1978 ◽  
Vol 7 (8) ◽  
pp. 811-812 ◽  
Author(s):  
Haruo Sekizaki ◽  
Masaaki Ito ◽  
Shoji Inoue
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Boron Trifluoride ◽  
Methyl Group

scholarly journals NOVEL REARRANGEMENT OF DIHYDROMAYURONE WITH BORON TRIFLUORIDE IN ACETIC ACID-ACETIC ANHYDRIDE

1978 ◽  
Vol 7 (11) ◽  
pp. 1191-1194 ◽  
Author(s):  
Haruo Sekizaki ◽  
Masaaki Ito ◽  
Shoji Inoue
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Boron Trifluoride

Tetracyclic triterpenes. VIII. The skeletal rearrangement of 3β-acetoxy-9α,11α-epoxy-5α-lanostan-7-one: 13- and 10-methyl group migration

1985 ◽  
Vol 63 (6) ◽  
pp. 1280-1286 ◽  
Author(s):  
Zdzisław Paryzek ◽  
Roman Wydra
Keyword(s):  
Acetic Anhydride ◽  
Spectral Data ◽  
Boron Trifluoride ◽  
Boron Trifluoride Etherate ◽  
Major Product ◽  
Chemical Transformations ◽  
Skeletal Rearrangement ◽  
Methyl Group ◽  
Group Migration

The boron trifluoride etherate catalyzed rearrangement of 3β-acetoxy-9α, 11α-epoxy-5α-lanostan-7-one (1) in acetic anhydride resulted in formation of 19(10 → 9β)abeo compounds 2 and 4 along with 18(13 → 12β)abeo compound 5, as the major product. These structures are supported by spectral data and chemical transformations. The possible mechanism of the rearrangement is discussed.

The Chlorination of Some Substituted 2,4-Dimethylphenols

1994 ◽  
Vol 47 (2) ◽  
pp. 289 ◽  
Author(s):  
JLM Gordon ◽  
MP Hartshorn ◽  
RJ Martyn ◽  
AJ Morgan ◽  
WT Robinson ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Acetic Acid ◽  
Carbon Tetrachloride ◽  
Acetic Anhydride ◽  
Methyl Group ◽  
X Ray

Chlorination reactions of 2-chloro-3,4,6-trimethylphenol (4), 2-chloro-4,6-dimethylphenol (5) and 3-chloro-2,4,6-trimethylphenol (6) are described. In acetic acid or acetic anhydride solution, chlorinations yield predominantly the corresponding 4-chlorocyclohexa-2,5-dienones (8), (17a) and (29), but in carbon tetrachloride containing pyridine products are formed which result from the modification of the 4-methyl group in each substrate. X-Ray crystal structure analyses are reported for compounds (7), (14), (28) and (31).

Synthetic routes to 2′,3′-cyclopropanated and 2′,3′-unsaturated nucleosides

1977 ◽  
Vol 55 (23) ◽  
pp. 3996-4001 ◽  
Author(s):  
Steve Yik-Kai Tam ◽  
Bert Fraser-Reid
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Boron Trifluoride ◽  
Synthetic Routes ◽  
Neutral Conditions

Cyclopropyl glycopyranosides which solvolyze via a stabilized cyclopropyl carbinyl-oxocar-bonium ion react under neutral conditions with nucleoside bases in nitromethane at 200 °C to give good yields of the corresponding cyclopropanated nucleosides. Under similar conditions hex-2-enopyranosides (which solvolyze by allyl-oxocarbonium ions) do not react. However, under catalysis by mercuric bromide or acetic acid, the corresponding 2′,3′ unsaturated nucleosides are formed although accompanied by appreciable amounts of 1′,2′-unsaturated-3′-nucleosides. Formation of the latter may be avoided if the hex-2-enopyranosides are first converted to the hex-2-enopyranosyl acetates by treatment with boron trifluoride and acetic anhydride. The derived acetates react with the nucleoside bases without catalysis to give anomeric mixtures of nucleosides, there being no trace of the unwanted 3′-nucleosides.

An unusual reaction of a bridged triterpenoid α-diketone with acetic anhydride

1991 ◽  
Vol 56 (12) ◽  
pp. 2917-2935 ◽  
Author(s):  
Eva Klinotová ◽  
Václav Křeček ◽  
Jiří Klinot ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Acetic Anhydride ◽  
Spectral Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Condensation Products ◽  
Unsaturated Lactones ◽  
C Nmr

3β-Acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) reacts with acetic anhydride in pyridine under very mild conditions affording β-lactone IVa and γ-lactones Va and VIIa as condensation products. On reaction with pyridine, lactones Va and VIIa undergo elimination of acetic acid to give unsaturated lactones VIIIa and IXa, respectively. Similarly, the condensation of 20β,28-epoxy-21,22-dioxo-18α,19βH-ursan-3β-yl acetate (IIIb) with acetic anhydride leads to β-lactone IVb and γ-lactone Vb; the latter on heating with pyridine affords unsaturated lactone VIIIb and 21-methylene-22-ketone Xb. The structure of the obtained compounds was derived using spectral methods, particularly 1H and 13C NMR spectroscopy; structure of lactone IVa was confirmed by X-ray diffraction.

Sign in / Sign up

Export Citation Format

Share Document