Gless, Bengt H. et al. published their research in Journal of Organic Chemistry in 2018 | CAS: 3326-34-9

5-Amino-3′,6′-dihydroxy-3H-spiro[isobenzofuran-1,9′-xanthen]-3-one (cas: 3326-34-9) belongs to benzofurans derivatives.Benzofuran is one of the most significant oxygen-containing heterocycles consisting of fused benzene and furan ring, which are widely presented in various naturally occurring and synthetically active compounds. Benzofurans are stable towards alkali and readily polymerize on treatment with sulfuric acid, due to which they are useful for the preparation of low cost chemically relatively inert resins.COA of Formula: C20H13NO5

Direct peptide cyclization and one-pot modification using the MeDbz linker was written by Gless, Bengt H.;Olsen, Christian A.. And the article was included in Journal of Organic Chemistry in 2018.COA of Formula: C20H13NO5 This article mentions the following:

The one-pot synthesis and modification of cyclic peptides through a self-cleaving on-resin protocol is described. We apply Dawson’s MeDbz linker to achieve direct intramol. peptide cyclization by thioesterification followed by S → N acyl shift. This native chem. ligation approach requires no activating additive and allows direct modification of the crude cyclic peptides in one-pot. The strategy was applied to synthesize 5 cyclic peptide natural products of varying ring size. Finally, one-pot modifications include desulfurization, fluorophore conjugation, and intramol. disulfide formation. In the experiment, the researchers used many compounds, for example, 5-Amino-3′,6′-dihydroxy-3H-spiro[isobenzofuran-1,9′-xanthen]-3-one (cas: 3326-34-9COA of Formula: C20H13NO5).

5-Amino-3′,6′-dihydroxy-3H-spiro[isobenzofuran-1,9′-xanthen]-3-one (cas: 3326-34-9) belongs to benzofurans derivatives.Benzofuran is one of the most significant oxygen-containing heterocycles consisting of fused benzene and furan ring, which are widely presented in various naturally occurring and synthetically active compounds. Benzofurans are stable towards alkali and readily polymerize on treatment with sulfuric acid, due to which they are useful for the preparation of low cost chemically relatively inert resins.COA of Formula: C20H13NO5

Referemce:
Benzofuran – Wikipedia,
Benzofuran | C8H6O – PubChem