Isochromans from 2-(3′,4′-dihydroxy)phenylethanol

Microwave‐accelerated Synthesis of Some (±)‐1‐Aryl‐5‐chloroisochromans

“…8 The reaction time varies from 1-day to several days and despite this in some cases the reaction is not complete. 17,18 In the present study, a variety of aromatic aldehydes were condensed with 2-(2-chlorophenyl)ethanol, a non-activated substrate, in the presence of a catalytic amount of a very mild acid catalyst, p-toluenesulfonic acid by microwave irradiation (Scheme 1). Commercial (2-chlorophenyl)-acetic acid was reduced using sodium boron hydride in THF/methanol to afford 2-(2-chlorophenyl)ethanol.…”

One‐Pot Synthesis of 6‐Hydroxyisochromans: The Example of Demethyl‐oxa‐coclaurine

“…[4] This modified procedure allows for the direct reaction between the two starting compounds, 3 and 4, without requiring protecting groups. We proposed a three step mechanism [4] for the oxa-PictetϪSpengler reaction, as depicted in Scheme 1.…”

“…[4] This modified procedure allows for the direct reaction between the two starting compounds, 3 and 4, without requiring protecting groups. We proposed a three step mechanism [4] for the oxa-PictetϪSpengler reaction, as depicted in Scheme 1. The first step, the acid-catalyzed formation of the hemiacetal is followed by water loss, which provides the reactive intermediate that finally undergoes intramolecular electrophilic aromatic substitution, in the activated position para to the hydroxyl group.…”

“…The oxygenated version of this reaction was reported for the first time by Wunsch and Zott in 1992 and denominated ''the oxa-PictetϪSpengler reaction.'' [3] In previous work we proposed modifications to this reaction, [4] the results led us to hypothesize that this modified version could be generalized to obtain oxygenated analogues of benzyl-tetrahydroisoquinoline alkaloids (i.e. 1-benzyl-isochromans).…”

Synthesis, Characterization, Anti-Inflammatory and in Vitro Antibacterial Activity of Some (±)-1-Aryl-7,8-Dichloroisochromans

“…The reaction time varies from 1-day to several days and despite this the reaction is not complete in some cases [21]. Commercial 2-(3,4-dichlorophenyl)acetic acid was reduced using sodium boron hydride in THF/methanol to afford 2-(3,4-dichlorophenyl)ethanol [22].…”