Photolysis of benzaldehyde in solution: the products
作者:J. S. Bradshaw、R. D. Knudsen、W. W. Parish
DOI:10.1039/c39720001321
日期:——
Benzaldehyde when irradiated in benzene yielded almost equal amounts of benzoin (I), deoxybenzoin (II), and 1,2-diphenylethane-1,2-diol (III); in ethanol the main product was (III) with only a trace of (I); while in hex-1-yne, seven isolable products were (I), (II), (III), heptanophenone (IV), cis-hept-2-eno-phenone (V), trans-hept-2-enophenone (VI), and 2-n-butyl-1,4-diphenylbutane-1,4-dione (VII)
Rhodium-mediated cyclopentane construction can compete with .beta.-hydride elimination: synthesis of (.+-.)-tochuinyl acetate
作者:Douglass F. Taber、Michael J. Hennessy、James P. Louey
DOI:10.1021/jo00028a011
日期:1992.1
Rhodium(II) carboxylate catalyzed C-H insertion to form a cyclopentane is shown to compete effectively with beta-hydride elimination, except when the beta-hydrogen is ternary. Cyclization of diazo ester 27 gives 28, which is converted in three steps to (+/-)-tochuinyl acetate 25. Both the cyclization to form 28 and the alkylation of 28 proceed with remarkable diastereoselectivity.
Conjugate reduction of .alpha.,.beta.-acetylenic ketones and esters by diisobutylaluminum hydride-hexamethylphosphoric triamide