109664-02-0Relevant articles and documents
Quinone derivatives by chemical transformations of 16-hydroxycarnosol from Salvia species
Marrero, Joaquin Gonzalez,Andres, Lucia San,Luis, Javier Gutierrez
, p. 1524 - 1529 (2005)
The known diterpenes 12,16-epoxycarnosol (2), isotanshinone II (6), and (+)-neocryptotanshinone (8) were obtained by partial synthesis from 16-hydroxycarnosol (1), a C-16 hydroxylated abietatriene diterpene isolated in relative abundance from the aerial part of Salvia mellifera GREENE. The physical and spectroscopic data of these semisynthetic diterpenes were identical to those given for the natural ones in the literature. These abietane diterpenes have very interesting biological activities and the semisynthetic approach described here represents an alternative to obtain them from other major diterpenes isolated from Salvia species. Additionally, seven new semisynthetic diterpene analogues, 11,14-dioxo-12,16-epoxy-8,12-abietadien-20,7β-olide (3), 11,14-dioxo-12,16-epoxy-8,12,15(16)-abietatrien-20,7β-olide (4), 15,16-didehydro-12,16-epoxycarnosol (5), 1-oxoisotanshinone II (7), 16-hydroxycolumbaridione (9), 12,16-diacetoxycolumbaridione (10), and 14-methoxy-12,16-epoxycarnosol (13), were obtained from 1. The structures of the new compounds were established based on their spectroscopic data.
Synthesis and vasodilative activity of tanshinone IIA derivatives
Bi, Yue-Feng,Xu, Hai-Wei,Liu, Xiao-Qing,Zhang, Xiao-Juan,Wang, Zhen-Ji,Liu, Hong-Min
scheme or table, p. 4892 - 4894 (2010/10/02)
A series of 2,2′-(substituted methylene)bis-(1,6,6-trimethyl-6,7,8,9- tetrahydrophenanthro[1,2-b]furan-10,11-dione) derivatives were synthesized by the reaction of tanshinone IIA (D1) and aromatic aldehyde in the presence of p-TsOH. Bromination derivative of D1 and hydrolysis product of cryptotanshinone (D2) were also prepared in this work. Vasodilation activity in vitro of them was valuated on the contractile response of vascular thoracic aorta smooth muscle from Wistar rats for the first time. Most of them exhibited a concentration-dependent inhibition on the contractile response of norepinephrine.
Atomatic Annulation Strategy for the Synthesis of Angularly-Fused Diterpenoid Quinones. Total Synthesis of (+)-Neocryptotanshinone, (-)-Cryptotanshinone, Tanshinone IIA, and (+/-)-Royleanone
Danheiser, Rick L.,Casebier, David S.,Firooznia, Fariborz
, p. 8341 - 8350 (2007/10/02)
The application of a photochemical aromatic annulation strategy in highly efficient total syntheses of several diterpenoid quinones isolated from the traditional Chinese medicine Dan Chen is reported.The pivotal step in each synthesis involves the assembly of the key tricyclic intermediate via the application of a recently developed "second generation" photochemical aromatic annulation method for the construction of highly substituted aromatic systems.In the total synthesis of neocryptotanchinone, the synthesis of the requisite diazo ketone anulation substrate 7 was achieved using paladium-mediated coupling reactions and an intramolecular Friedel-Crafts cyclization to form key carbon-carbon bonds.The pivotal aromatic annulation reaction was then accomplished by irradiating a solution of the diazo ketone 7 and the readily availabe siloxyalkyne 6 in benzene at room temperature.The desired tricyclic phenol 16 was produced in 58-65percent yield and was then converted to (+)-neocryptotanshinone (1) by treatment with tetra-n-butylammonium fluoride in the presence of oxygen.Cyclization to generate (-)-cryptotanshinone (2) was accomplished in high yield by brief exposure of 1 to an ethanolic solution of concentrated sulfuric acid, and dehydrogenation of 2 with DDQ furnished tanshinone IIA (3).As a further demonstration of the utility of the photochemical aromatic annulation strategy in the construction of angularly-fused diterpenes, the total synthesis of (+/-)-royleanone (4) was also investigated.Irradiation of a solution of the diazo ketone 18 and siloxyalkyne 25 produced the tricyclic intermediate 26, which was converted in two steps to royleanone by desilylation and oxidation.
