First synthesis of 2-(2,4,4-Trimethyl-3,4-dihydro-2H-benzo[h]chromen-2-yl)-1-naphthol and 3-(2,4,4-Trimethyl-3,4-dihydro-2H-benzo[g]chromen-2-yl)-2-naphthol from 1-and 2-Naphthol derivatives

Abstract

Two new structurally isomeric, 2-(2,4,4-trimethyl-3,4-dihydro-2H-benzo[h]chromen-2-yl)-1-naphthol (1) and 3-(2,4,4-trimethyl-3,4-dihydro-2H-benzo[g]chromen-2-yl)-2-naphthol (3) have been synthesized from 2-acetyl-1-naphthol and ethyl-3-hydroxy-2-naphthoate, respectively, involving Grignard reaction, dehydration of the corresponding tertiary alcohols, and hetero Diels-Alder dimerization. The two benzochromenes (1 and 3) have been fully characterized by IR, NMR, and HRESIMS data. Their structures are further supported by crystallography of their corresponding acetates (2 and 4).