Payne ring-opening rearrangement

Sharpless and Masumune have applied the AE reaction on chiral allylic alcohols to prepare all 8 of the L-hexoses. ° AE reaction on allylic alcohol 52 provides the epoxy alcohol 53 in 92% yield and in >95% ee. Base catalyze Payne rearrangement followed by ring opening with phenyl thiolate provides diol 54. Protection of the diol is followed by oxidation of the sulfide to the sulfoxide via m-CPBA, Pummerer rearrangement to give the gm-acetoxy sulfide intermediate and finally reduction using Dibal to yield the desired aldehyde 56. Homer-Emmons olefination followed by reduction sets up the second substrate for the AE reaction. The AE reaction on optically active 57 is reagent... 

Thus far, we have discussed nucleophilic ring opening in 2,3-epoxy-l-ol taking place at the C-2 and C-3 positions (see compound 58 in Scheme 4-19). However, in the presence of a base, nucleophilic ring opening can take place at C-l via Payne rearrangement to produce 2,3-diol.36 For example, compound 1,2-... 

Scheme 4-19. Payne rearrangement and subsequent ring opening.

Scheme 4-20 exemplifies PhS- attack mediated by a Payne rearrangement. The selective ring-opening product can be applied to prepare tetritols.37... 

Scheme4.83. Payne rearrangement followed by thiol-mediated ring opening of 3-substituted 2,3-epoxy-l-propanols [365],...

Treatment of certain 2-(hydroxymethyl)aziridines with base can lead to an intramolecular ring-opening reaction to yield an cc-amino epoxide, a reaction analogous to the Payne rearrangement of (hydroxymethyl)epoxides. For example, treatment of the aziridine 109 with potassium tert-butoxide provides the epoxide 110 in good yield. 

Hydroxymethylaziridine 67 undergoes ring opening in the presence of either carbon- or heteroatom-based nucleophiles upon treatment with 2 equiv of potassium hydride to provide the t)7aminoalcohol derivative 69. The key step of the reaction is considered to be an aza-Payne rearrangement of the deprotonated aziridine methanol to the... 

Payne rearrangement followed by nucleophilic epoxide ring-opening ... 

Ibuka, T., Nakai, K., Akaji, M., Tamamura, H., Fujii, N., Yamamoto, Y. An aza-Payne rearrangement-epoxide ring opening reaction of 2-aziridinemethanols in a one-pot manner a regio- and stereoselective synthetic route to diastereomerically pure N-protected 1,2-amino alcohols. Tetrahedron 1996, 52, 11739-11752. 

Of course, the nucleophilic ring-opening can also occur in an intramolecular fashion, as demonstrated by the Payne rearrangement of the epoxyalcohol 75 to form the corresponding secondary alcohol (76). Dess-Martin oxidation of the latter provided expoxyketone 77 formally derived from P-disubstituted enones, which are difficult to access directly in an enantioselective fashion <01JCS(P1)1109>. 

The reaction of 32 with an aqueous solution of dimethylamine was reported to produce a mixture of 103,104, and 105 in a ratio of 11.1 1.0 2.9, ° and this case served as a reference for our studies. Formation of 103 under these conditions resulted from C-1 attack of Me2NH after base-mediated Payne rearrangement of 32. In spite of the inherent instability of the rearranged intermediate Int-17, which contains the alkoxide of a sec-OH as well as a monosubstituted epoxide, a possible kinetic preference for reaction at the unhindered C-1 position of Int-17 would rationalize why 103 was formed as the main product. The same situation was already discussed in Scheme 10.9. Compounds 104 and 105, meanwhile, formed in a 1 3 ratio by direct ring opening of 32. This analysis led to the inference that a part of ( )-syn-92 would first be converted to the more favorable (Z)-anti-93 in a basic media, so that the amine would attack either C-1 or C-2 of (Z)-antz-93 as well as C-2 in (E)-syn-92 giving a mixture of syn,ant/-102, syn,syn-100, and anti,anti-100, respectively. 

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