Colletofurans A–E, 1-Octyl-1,3-dihydroisobenzofuran Derivatives from Colletotrichum boninense AM-12-2

Abstract

3-(3-Hydroxy-2-(hydroxymethyl)phenyl)propanoic acid, 2-hydroxymethyl-3-hydroxy-(E)-cinnamic acid, and colletofurans A−E were isolated from Colletotrichum boninense AM-12−2. Colletofurans A−E are the first natural compounds featuring a 1-octyl-1,3-dihydroisobenzofuran core. Their structures were initially established by 1D/2D-NMR and HRESITOFMS. Mosher's ester method was used to determine the absolute configurations of secondary alcohols in colletofurans A−C. The structures of colletofurans A and B−E were further confirmed by DFT GIAO calculations and the X-ray crystalline sponge method, respectively.

Squaramide-Catalyzed Asymmetric Intramolecular Oxa-Michael Reaction of α,β-Unsaturated Carbonyls Containing Benzyl Alcohol: Construction of Chiral 1-Substituted Phthalans

“…In particular, chiral 1,3-dihydroisobenzofuran, commonly referred to as phthalan, is abundant in bioactive natural products, which display pharmacological properties such as antibacterial, anti-inflammatory, antidepressive, antioxidant, and anti-influenza (Figure ). Several synthetic methods have been developed for phthalans based on cyclization strategies . However, most reactions are limited to the synthesis of nonchiral phthalans.…”

Synthesis of 1,3-diselenyl-dihydroisobenzofurans via electrochemical radical selenylation with substituted o-divinylbenzenes and diselenides

“…Next, a set of solvents was screened and the reaction performed in MeCN : H 2 O (800 : 1 v/v) provided the best result (Table 1, entries 1 and 8-10). Further investigation of the conditions demonstrated that the reaction could not work with n-Bu 4 NBF 4 , n-Bu 4 NClO 4 , Et 4 NBF 4 , n-Bu 4 NBr, or KI as the electrolyte (Table 1, entries [11][12][13][14][15].…”

“…1,3-Dihydroisobenzofurans (phthalanes) widely exist in many natural products such as asperchalasines 11 and colletofurans (Scheme 1). 12 Besides, they also exist in biologically active molecules or pharmaceuticals such as citalopram and talopram, potent selective serotonin reuptake and norepinephrine transporter inhibitors, respectively. 13 As a result, a variety of synthetic approaches to 1,3-dihydroisobenzofuran derivatives have been reported.…”

Scalable Biomimetic Syntheses of Paeciloketal B, 1-epi-Paeciloketal B, and Bysspectin A

“…Benzannulated 5,5-spiroketals are relatively rare in nature (<20 reported), and a number have exhibited promising bioactivity, motivating research into their isolation and synthesis. − The novel benzannulated 5,5-spiroketal paeciloketal B ( 1a ) and its epimer 1- epi -paeciloketal B ( 1b ) were discovered in 2015. These natural products were isolated from the culture broth of Paecilomyces variotii , a fungus acquired from the giant jellyfish Nemopilema nomurai , which was collected from the South Korean Sea .…”