摘要:
The sulfoxide thermolysis of the diastereoisomeric methyl (3R,4aS, 10R)-6-methoxy-1-methyl-3-(phenylisulfinyl)-1,2,3,4,4a,5,10,10a-oct hydrobenzo[g]quinoline-3-carboxylates 3a and Yb in toluene yields, by loss of benzenesulfenic acid, an almost 1 : 1 mixture of the vinylogous urethane 2b and the isomeric alpha-aminoethyl enoate 2a. When this elimination is performed in acetic acid, the enoate 2a is formed rather selectively. The same solvent effects on the regioselectivity of the elimination of benzenesulfenic acid are observed with a simple sulfoxide of ethyl piperidine-3-carboxylate (7).