engleski

Synthesis of naphtho[2, 3-b]- and naphtho[1, 2-b]-fused thieno[2, 3-d][1]benzoxepins and thieno[2, 3-d][1]-benzothiepins

Synthesis of four novel classes of structurally related fused hetero-pentacyclic compounds, naphtho[2, 3-b]thieno[2, 3-d][1]benzothiepins (Ia), naphtho[1, 2-b]thieno[2, 3-d][1]benzothiepins (IIa), naphtho[2, 3-b]thieno- [2, 3-d][1]benzoxepins (Ib, c) and naphtho[1, 2-b]thieno[2, 3-d][1]benzoxepins (IIb, c), is described. The key intermediates were the tetracyclic ketones, benzo[b]-naphtho[f]-fused thiepinones 1a, b and oxepinones 1c-f, formed by intramolecular cyclization of the corresponding 2-naphthalenylthio- (2a, b) and 2-naphthalenyloxy-substituted (2c-f) phenylacetic acid derivatives. Reaction of ketones 1a-f with Vilsmeier reagent provided -chlorovinyl aldehydes 10a-f that readily cyclized with ethyl 2-mercaptoacetate to form thieno[2, 3-d]-fused derivatives of benzo-naphtho-thiepins 11a, b and benzo-naphtho-oxepins 11c-f. Reduction of ester group of 11a-f afforded final hydroxymethyl derivatives 12a-f.

thieno[2; 3-d]-fused benzo-naphtho-thiepins; thieno[2; 3-d]-fused benzo-naphtho-oxepins; tetracyclic ketones; thiophene annulation; structural characterization

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