Benzaldehyde Patemo Buchi reaction

The enol ether double bond contained within the ds-fused dioxa-bicyclo[3.2.0]heptene photoadducts can also be oxidized, in a completely diastereoselective fashion, with mCPBA. Treatment of intermediate XXII, derived in one step from a Patemo-Buchi reaction between 3,4-dimethylfuran and benzaldehyde, with mCPBA results in the formation of intermediate XXIII. Once again, consecutive photocycloaddition and oxidation reactions furnish a highly oxygenated system that possesses five contiguous stereocenters, one of which is quaternary. Intermediate XXIII is particularly interesting because its constitution and its relative stereochemical relationships bear close homology to a portion of a natural product known as asteltoxin. 

Allylic strain is employed in the Patemo-Buchi reaction of a silyl enol ether and benzaldehyde.79 Using a bulky or polar substituent y to the ether as stereogenic locus, diastereomerically pure oxetanes with four contiguous chiral centres have been prepared. 

The Patemo-Buchi reaction on furan has been studied from a theoretical point of view [42]. The HOMO of furan has an energy of 0.32 eV, and the atomic coefficients of this orbital (Fig. 3.3) are in agreement with an attack of the carbonyl oxygen on the a carbon. The structures of the possible adducts deriving from the attack of benzaldehyde in the a position of furan are depicted in Figure 3.4. The exo isomer is more stable (0.5 kcal mol 1) than the other isomer, in agreement with the experimental results. 

Fleming and Gao reported that the photocycloaddition of the trimethylsilyl ether of phenylpropenol with benzaldehyde proceeds with high stereoselectivity to give the fra/is-oxetane 60 in 20% yield. In competition to the Patemo-Buchi reaction, cis/trans isomerization leads to cis and trans isomers of the... 

Oxygen atoms in the tetrahydrofuran rings embedded in inositol-based tris(spirotetrahydrofuranyl)ionophores were useful as chelation sites towards selective alkali metal ion binding and as a result rodlike supramolecular ionic polymer frameworks were prepared and analyzed in this study <01JA4974>. The temperature and viscosity dependence of the spin-directed stereoselectivity of the Patemo-Buchi photocycloaddition reactions between 2,3-dihydrofuran and benzaldehyde were studied <01 AG(E)4684>. 

The photochemical [2 + 2]-cycloaddition reactions of carbonyl compounds with alkenes are known as the Paterno-Buchi reactions This reaction was first reported by the group of E. Patemo and G. Buchi on the reaction of benzaldehyde with 2-... 

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