ISSN:
0021-8383
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Photochemistry of Aminoketones. VIII. Diastereoselective Synthesis of 3-Hydroxy-prolinesGlycine esters react in two steps (aminoalkylation and N-acylation) to N-acyl-N-(β-benzoylethyl)-glycine ester 3. In less polar solvents these ketonic compounds are n,π*-excited by 300 nm irradiation. In ether 3* yield mixtures of aminocyclopropanoles 4, hydroxyprolines 5 and products of additions and cleavages. In benzene and cyclohexane/benzene, respectively, the regioselective photocyclization to 5 is favoured. Furthermore this hydroxyproline synthesis has the advantages of high diastereoselectivity yielding the (2,3) E-5 and of high overall-yields in connection with the one pot method. The influence of solvents and substituents on the regio- and diastereoselectivity are explained using a model with stabilization of special conformations of intermediates by dipol-dipol interactions.
Additional Material:
3 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prac.19853270108
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