BOchi

A regioselective aldol condensation described by Biichi succeeds for sterical reasons (G. Biichi, 1968). If one treats the diaidehyde given below with acid, both possible enols are probably formed in a reversible reaaion. Only compound A, however, is found as a product, since in B the interaction between the enol and ester groups which are in the same plane hinders the cyclization. BOchi used acid catalysis instead of the usual base catalysis. This is often advisable, when sterical hindrance may be important. It works, because the addition of a proton or a Lewis acid to a carbonyl oxygen acidifies the neighbouring CH-bonds. 

In Diels-Alder reactions a nitroolefin may function as an electron-deficient ene com-onent or a 1,2-dihydropyridine derivative may be used as a diene component. Both types of iactants often yield cyclic amine precursors in highly stereoselective manner (R.K. Hill, 1962 i. BOchi, 1965, 1966A). 

Submitted by H. Stetter, H. Kuhlmann, and G. Lorenz Checked by Benjamin G. Padilla and George BOchi... 

Richard E. Benson Arnold Bros9I George H. BOchi Herbert O. House... 

Richard T. Arnold Henry E. Baumgarten Richard E. Benson Virgil Boekelheide Ronald Breslow Arnold Brossi George H. BOchi T. L. Cairns James Cason Orville L. Chapman Robert M. Coates E. J. Corey William G. Dauben William D. Emmons... 

Szantay V, Tamas S, Marian L, Bochis G (1974) [Changes of hepatic blood flow in children as a function of age.] Rev Roum Med Intern, 11 91-93 (in French). 

PATERNO-BOCHI REACTION OF DIENYL AND ALLENYL SYSTEMS 165... 

PATERNO. BOcHI Z+J CyckjaddHIon Photochemical Z+Z cyciization o( caitenyis and oleflns to oxetanes... 

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