Date of Graduation
A synthetic approach to 2H-pyran (1) via von Braun reaction by using 5-N,N-dimethylamino-(Z)-3-pentenal (39) was elaborated. Various attempts to make the key precursor 39 by hydrolyzing 5-N,N-dimethylamino-(Z)-3-pentenal dimethyl acetal (56) and oxidizing 5-N,N-dimethylamino-(Z)-3-penten-1-ol (67) were unsuccessful. Stereocontrolled synthesis of (Z)-2,4-pentadienal (2) was accomplished, and experiments to trap its valence tautomer, 2H-pyran (1), albeit unsuccessful due to its ambient sensitivity, were described. The spectroscopic comparisons of (Z)-2,4-pentadienal (2) were carefully studied. Analogously, (Z)-3,5-hexadien-1-ol (120) was also synthesized by Peterson olefination. This constitutes a new methodology for the synthesis of conjugated diene.
Fang, Kang, "Synthetic Studies Toward 2H-Pyran - Stereocontrolled Synthesis Of (Z)-2,4-Pentadienal." (1984). Graduate Theses, Dissertations, and Problem Reports. 8836.