Synthesis and Photooxygenation of Linear and Angular Furocoumarin Derivatives as a Hydroxyl Radical Source: Psoralen, Pseudopsoralen, Isopseudopsoralen, and Allopsoralen

Abstract

Synthesis of linear and angular furocoumarins with new skeleton structure of potential photobiological feature interest was carried out through Williamson reaction of hydroxycoumarins with 3‐chloro‐2‐butanone followed by cyclization with polyphosphoric acid or by heating in a strongly alkaline solution. The photooxygenation reactions of synthesized furocoumarins were performed in chloroform and in the presence of tetraphenylporphyrin as singlet oxygen sensitizer (1O2). The photooxygenation reactions afforded the photocleaved product through [2 + 2] cycloaddition and the photooxygenated products through ene reaction and [4 + 2] cycloaddition. The photoproducts were isolated and fully characterized by spectral analyses.

CERTAIN CASES OF o-ALKOXYCINNAMIC ACIDS CREATION FROM COUMARINS IN O-ALKYLATION CONDITION

“…Наступними об'єктами дослідження були фурокумарини 18a-d. Дані сполуки легко синтезувати з 7-гідрокси-4-метилкумарину 19 за методом Робінсона [17][18][19][20], а саме: алкілюванням гідроксигрупи -галогенокетонами та наступним замиканням фуранового циклу в сильно лужному середовищі (рис. 6).…”

“…Вихідні сполуки синтезовані за методиками, наведеними в наступних джерелах: сполука 16а - [13], 16b - [12], 18a - [17], 18b - [18], 18c - [19], 18d - [20], 23 - [25]. 3-(2,4-Біс(2-етокси-2-оксоетокси)-5-(1-оксо-1H-ізохромен-3-іл)феніл)бут-2-енова кислота (25).…”

Sonochemistry as a General Procedure for the Synthesis of Coumarins­, Including Multigram Synthesis

“…The reaction mixture was poured over ice water, the separated solid was collected by filtration, and purified via recrystallization from MeOH; yield: 493 mg (2.8 mmol, 87%); white solid; mp 182.1-184.4 °C (Lit. 23…”

A concise synthesis of furo[3,2-c]coumarins catalyzed by nanocrystalline ZnZr4(PO4)6 ceramics under microwave irradiation

“…Therefore, searching for efficient and concise techniques for the synthesis of furocoumarins through multicomponent reactions is a remarkable challenge. A number of methods has been developed for the synthesis of furocoumarins in the presence of diverse catalysts such as pyridine or a mixture of AcOH and AcONH 4 [9], ionic liquid [BMIm]OH [10], Pd(CF 3 COO) 2 [11], CuBr 2 [12], Nmethylimidazolium [13], Et 3 N [14], Bu 3 P and Et 3 N [15], polyphosphoric acid or KOH [16] and Rh 2 (OAc) 4 [17].…”