The Properties of Certain Beta Oxanols

Kohler, E. P.; Bickel, Charles L.

doi:10.1021/ja01309a043

Cited by 7 publications

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“…Similarly, benzalaeetophenone oxide and phenyllithium give 2,3-epoxy-l, 1,3triphenyl-l-propanol and o-chlorobenzalacetophenone oxide gives the 3-(o-chlorophenyl) analog, identical with the compounds obtained by Kohler, Richtmyer, and Hester (141) and by Kohler and Bickel (140) with phenylmagnesium bromide. The difference in the reaction of benzalaeetophenone oxide and the p-methoxy compound with phenylmagnesium bromide was explained as due to activation of the oxirane ring by the anisyl group.…”

Section: Carotene Epoxidessupporting

confidence: 77%

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The Reaction between Grignard Reagents and the Oxirane Ring.

Gaylord¹,

Becker²

1951

Chem. Rev.

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Section: Carotene Epoxidessupporting

confidence: 77%

“…oxide was prepared by Kohler and Bickel(140).From phenylmagnesium bromide at -15°C. the expected oxanol was obtained, which reacted with the ethyl Grignard reagent to give diphenylethylcarbinol: o-CICeHiCH-CHCOC.H, + C.H,MgBr -and phenyllithium at -18°C.…”

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confidence: 99%

The Reaction between Grignard Reagents and the Oxirane Ring.

Gaylord¹,

Becker²

1951

Chem. Rev.

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“…A casual examination of the reaction sequence VIII + I X I + V or VI would favor the assignment of the structure V. Such a structure would not be I unreasonable because the 3,4-epoxytetrahydrofuran system is not very strained and has been prepared in the unsubstituted form (14,15) as well as in the sugar series (16,17). However, it is necessary to consider the remarkable ease of rearrangement of a,P-epoxyalcohols analogous to I X by transposition of hydroxyl and epoxide (0-oxanol rearrangement) (13). Thus 2,3-epoxy-1-chloro-2,4-bis(p-chlorophenyl)-4-hexanol (IX) on treatment with alcoholic alkali could first rearrange by alcohol epoxide transposition to 3,4-epoxy-1-chloro-2,4-bis(p-chloropheny1)-2-hexanol (X) and then dehydrochlorinate to 1,2,3,4-diepoxy-2,4-bis(p-chloropheny1)hexane (VI).…”

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confidence: 99%

SELF-CONDENSATION OF p-CHLOROPHENACYL CHLORIDE IN THE PRESENCE OF GRIGNARD REAGENT

Kulka¹

1964

Can. J. Chem.

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A crystalline by-product, formed in the reaction of p-chlorophenacyl chloride (I) with ethylmagnesium chloride, has been identified as 1,3-dichloro-2,4-bis(p-ch1orophenyl)-2,4-hexanediol (IV). Its formation has been attributed t o aldolization of I followed by reaction with Grignard reagent a t the carbonyl function. The dehydrochlorination of IV yielded one of two possible compounds to which the diepoxide structure VI was assigned on the basis of n.m.r. spectra. The dehydrochlorinated product (VI) was synthesized from 1-chloro-2,3-epoxy-2,4-bis(p-chloropheny1)-4-butanone (VIII) by treatment with ethylmagnesium chloride followed by reaction of the resulting epoxy alcohol IX with alcoholic alkali. I t is suggested that the epoxy alcohol I X did not dehydrochlorinate directly to the 3,4-epoxytetrahydrofuran derivative V but instead rearranged first by epoxide alcohol transposition t o X and then dehydrochlorinated to 1,2,3,4-diepoxy-2,4-bis(p-ch1orophenyl)hexane (VI).The condensation of p-chlorophenacyl chloride (I) with ethylmagnesium chloride produced the normal compound, l-chloro-2-~-chlorophenyl-2-butanol (11) (1) as well as a crystalline by-product. The latter was formed in higher yield when the order of addition was reversed and the Grignard reagent was added to I. This investigation describes the properties and identification of this crystalline by-product and provides evidence for the mechanism of its formation.The infrared spectrum of this con~pound showed the presence of hydroxyl groups and the absence of carbonyl groups. The OH band appeared a t 3.0 p (3 333 cm-I), a shift from the norlnal which indicated hydrogen bonding. The reluctance of the conlpound to react with phenyl isocyanate or with acetic anhydride suggested the presence of tertiary hydroxyl groups. Of the possible modes of formation of the hydroxyl group from the carbonyl group, aldolization appeared to be the most likely. Analysis of the unlino~vn compound provided the formula (CgI-IgC120), with half the chlorine not removable and the other half easily removable by dehydrochlorination with cold methanolic or ethanolic potassium hydroxide. The dehydrochlorination was accompanied by loss of the hydroxyl groups, as evidenced by infrared spectra, and this indicated epoxide formation froin a chlorohydrin.The molecular weight of the unlinown compound could not be determined by the Rast method because it liberated hydrogen chloride on heating. The dehydrochlorinated compound, on the other hand, though sensitive to acids and bases, was more stable to heat and could be distilled in vacuo. Analysis and n~olecular weight determinations of the dehydrochlorinated compound gave the empirical formula (CgHBC10)2 from ~vhich the formula (CgHgC120)Z could be deduced for the chlorohydrin. On the basis of the above evidence the structure IV was assigned to the by-product of the Grignard reaction and the structure V or VI to the dehydrochlorinated product. Degradation studies showed that IV could be cleaved by phosphorus pentoxide in boiling benzene t...

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Epoxide Migration (Payne Rearrangement) and Related Reactions

Hanson

2002

Organic Reactions

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Under a variety of basic conditions, 2,3‐epoxy alcohols rearrange with inversion at C‐2. The reaction, originally referred to in the literature as the β‐oxanol rearrangement, is now exclusively referred to as epoxide migration or Payne rearrangement. Epoxide migration is reversible, often leading to a mixture of epoxy alcohol isomers. Furthermore, in the presence of hydroxide or other nucleophiles, in situ opening of the equilibrating species may be observed. When such opening is desired, epoxide migration becomes a powerful method for the introduction of functionality into a substrate containing a 2,3‐epoxy alcohol moiety. However, when opening is not desired, epoxide migration can become a significant problem. The epoxide migration process lends itself to other synthetically useful manipulations. For example, the anionic equilibrating species may also be trapped with electrophiles such as alkyl and silyl halides, alkyl sulfonates, and epoxides. Electrophilic trapping may be inter‐ or intramolecular, and has been used as a means of delivering functionality to either C‐2 or C‐3 selectively. The intent of this chapter is to provide a comprehensive review of epoxide migration, including factors influencing the equilibrium position, conditions leading to in situ epoxide opening, and examples of electrophilic trapping. The reaction is discussed in relation to its utility as a synthetic method as well as its prevention as an unwanted side reaction. Related rearrangements in which either the epoxide or hydroxy oxygen has been replaced with nitrogen or sulfur have also been studied. These reactions, referred to in the literature as aza‐Payne and thia‐Payne rearrangements, respectively, are comprehensively included in this chapter as well. For the purposes of this discussion, the term “forward” aza‐Payne rearrangement refers to the direction of reaction leading from oxirane to aziridine. Similarly, “forward” thia‐Payne rearrangement refers to the direction of reaction leading from oxirane to thiirane. In the case of aza‐Payne rearrangements, both forward and reverse reactions have been effected, and in this chapter the term “reverse” aza‐Payne rearrangement refers to reactions leading from aziridine to oxirane. Epoxides have long been considered important in the chemistry of carbohydrates, and epoxide migration in the context of carbohydrate chemistry has been discussed in several reviews. In addition, particularly since discovery of the catalytic asymmetric epoxidation of allylic alcohols and the rise in importance of enantiomerically enriched acyclic epoxy alcohols, epoxide migration with in situ opening in acyclic systems has been much studied. The tabular survey summarizes the literature of epoxide migration and related reactions, including equilibration, in situ opening and trapping, aza‐Payne rearrangements, and thia‐Payne rearrangements, from 1931 to 1999. Reports referring to reactions involving addition at C‐1 or C‐3 without inversion of stereochemistry at C‐2 as “Payne rearrangements” are not covered in this review.

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The Properties of Certain Beta Oxanols

Cited by 7 publications

References 0 publications

The Reaction between Grignard Reagents and the Oxirane Ring.

The Reaction between Grignard Reagents and the Oxirane Ring.

SELF-CONDENSATION OF p-CHLOROPHENACYL CHLORIDE IN THE PRESENCE OF GRIGNARD REAGENT

Epoxide Migration (Payne Rearrangement) and Related Reactions

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