Abstract
In a synthetic endeavor to find out a general route to morphinandienones [3] via p-quinol acetates [7a], 8-chloro-p-quinol acetates [13a, b] have been prepared from 1-benzyl-8-chloro1, 2, 3, 4-tetrahydroisoquinolin-7-ols [12a, b] and subjected to acid treatment with trifluoroacetic acid giving the desired 8-chloromorphinandienones [14a, b] along with 9-chloroisopavines [15a, b] and 4β-hydroxyaporphines [17a, b]. An explanation for the unexpected formation of the latter two is presented.
Quite similarly, 8-chlorohomomorphinandienones [14c∼e], 9-chlorohomoisopavines [15c∼e], and 4β-hydroxyhomoaporphines [17c, d] have been obtained starting from the homologous p-quinol acetates [13c∼e]. Structure assignment of [17c] and [17d] has been based on the comparison of their diacetates with the authentic samples [18c and d], derived from monoacetates [19c and d], which have been afforded on lead tetraacetate oxidation of 1-hydroxyhomoa porphines [9a, b] respectively.
Finally, predominant formation of the desired homomorphinandienones [14c∼e] has been achieved by the oxidation of 8-chloro-1-phenethyl-1, 2, 3, 4-tetrahydroisoquinolin-7-ols[12c∼e] in a mixture of trifluoroacetic acid and acetic acid.
