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All 3 posts Subject: Epoxide -> Ketone Rearrangement Review Please login to post Down

Rhodium
(Chief Bee)
10-03-03 23:59
No 462464
User Picture       Epoxide -> Ketone Rearrangement Review
(Rated as: excellent)

This is an excellent article, with a very good review of other methods which has been used for the rearrangement of epoxides to carbonyl compounds, and for our interests the rearrangement of propenylbenzene epoxides to phenylacetones is the most interesting transformation (such as isosafrole expoxide to MDP2P).

The reviewed methods include Pd(OAc)₂/PPh₃, BF₃·Et₂O, MgBr₂, lithium salts, Indium chloride, Bismuth salts like BiOClO₄/Bi(OTf)₃, methylaluminium bis(4-bromo-2,6-di-tert-butylphenoxide) (MABR) as well as their own invention, to use catalytic (1 mol%) IrCl₃·xH₂O, which gives 100% conversion of propenylbenzene epoxide to P2P (THF/50°C/2h).

Iridium-Catalyzed Meinwald Epoxide Rearrangement
Iyad Karamé, M. Lorraine Tommasino and Marc Lemaire
Tet. Lett. 44(41), 7687-7689 (2003) (https://www.rhodium.ws/chemistry/meinwald.rearr.ircl3.html)

Abstract
A novel and easy to handle procedure for the regioselective rearrangement of epoxides has been developed, based on an iridium catalyst.

Rhodium
(Chief Bee)
01-10-04 00:30
No 481505
User Picture       Fluorosulfuric Acid 4 Epoxide Rearrangement
(Rated as: good read)

Reaction of Phenyl-1,2-Epoxypropane with Fluorosulfuric Acid
J. Org. Chem. 46, 2920-2923 (1981)

To 6 mL of FSO₃H cooled in an ice-bath was added 2.5 g of propenylbenzene epoxide dropwise in 50 min. The black reaction mixture was carefully added to ice in the presence of 200 mL of CHCl₃. After extraction of the aqueous phase, it was saturated with NaCl and extracted with 200 mL of CHCl₃. The combined organic extracts were washed with saturated NaCl solution (3x200 mL), dried over MgSO₄, filtered, and concentrated under vacuum to yield 2.2 g (88%) of phenyl-2-propanone as an oil.

^{The Hive - Clandestine Chemists Without Borders}

Rhodium
(Chief Bee)
06-21-04 22:39
No 514676
User Picture       Lewis acid-promoted Epoxide Rearrangement
(Rated as: good read)

Lewis acid-promoted selective rearrangement of trisubstituted epoxides to aldehydes or ketones
Keiji Maruoka, Noriaki Murase, Ronan Bureau, Takashi Ooi and Hisashi Yamamoto
Tetrahedron 50(12), 3663-3672 (1994) (https://www.rhodium.ws/pdf/epoxide2ketone.mabr.pdf)

Abstract
Rearrangement of trisubstituted epoxides has been effected under the influence of various Lewis acids. Among these, methylaluminum bis(4-bromo-2,6-di-tert-butylphenoxide) (MABR) can be selectively rearranged from trisubstituted epoxides to aldehydes, while antimony pentafluoride is employable for selective rearrangement to ketones under mild conditions.

^{The Hive - Clandestine Chemists Without Borders}

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	All 3 posts		Subject: Epoxide -> Ketone Rearrangement Review		Please login to post		Down


		Rhodium (Chief Bee) 10-03-03 23:59 No 462464				Epoxide -> Ketone Rearrangement Review (Rated as: excellent)
						This is an excellent article, with a very good review of other methods which has been used for the rearrangement of epoxides to carbonyl compounds, and for our interests the rearrangement of propenylbenzene epoxides to phenylacetones is the most interesting transformation (such as isosafrole expoxide to MDP2P). The reviewed methods include Pd(OAc)₂/PPh₃, BF₃·Et₂O, MgBr₂, lithium salts, Indium chloride, Bismuth salts like BiOClO₄/Bi(OTf)₃, methylaluminium bis(4-bromo-2,6-di-tert-butylphenoxide) (MABR) as well as their own invention, to use catalytic (1 mol%) IrCl₃·xH₂O, which gives 100% conversion of propenylbenzene epoxide to P2P (THF/50°C/2h). Iridium-Catalyzed Meinwald Epoxide Rearrangement Iyad Karamé, M. Lorraine Tommasino and Marc Lemaire Tet. Lett. 44(41), 7687-7689 (2003) (https://www.rhodium.ws/chemistry/meinwald.rearr.ircl3.html) Abstract A novel and easy to handle procedure for the regioselective rearrangement of epoxides has been developed, based on an iridium catalyst.



		Rhodium (Chief Bee) 01-10-04 00:30 No 481505				Fluorosulfuric Acid 4 Epoxide Rearrangement (Rated as: good read)
						Reaction of Phenyl-1,2-Epoxypropane with Fluorosulfuric Acid J. Org. Chem. 46, 2920-2923 (1981) To 6 mL of FSO₃H cooled in an ice-bath was added 2.5 g of propenylbenzene epoxide dropwise in 50 min. The black reaction mixture was carefully added to ice in the presence of 200 mL of CHCl₃. After extraction of the aqueous phase, it was saturated with NaCl and extracted with 200 mL of CHCl₃. The combined organic extracts were washed with saturated NaCl solution (3x200 mL), dried over MgSO₄, filtered, and concentrated under vacuum to yield 2.2 g (88%) of phenyl-2-propanone as an oil. ^{The Hive - Clandestine Chemists Without Borders}



		Rhodium (Chief Bee) 06-21-04 22:39 No 514676				Lewis acid-promoted Epoxide Rearrangement (Rated as: good read)
						Lewis acid-promoted selective rearrangement of trisubstituted epoxides to aldehydes or ketones Keiji Maruoka, Noriaki Murase, Ronan Bureau, Takashi Ooi and Hisashi Yamamoto Tetrahedron 50(12), 3663-3672 (1994) (https://www.rhodium.ws/pdf/epoxide2ketone.mabr.pdf) Abstract Rearrangement of trisubstituted epoxides has been effected under the influence of various Lewis acids. Among these, methylaluminum bis(4-bromo-2,6-di-tert-butylphenoxide) (MABR) can be selectively rearranged from trisubstituted epoxides to aldehydes, while antimony pentafluoride is employable for selective rearrangement to ketones under mild conditions. ^{The Hive - Clandestine Chemists Without Borders}

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