32384-42-2Relevant articles and documents
[2+2] Photoadditions with chiral 2,5-cyclohexadienone synthons
Lange, Gordon L.,Humber, Craig C.,Manthorpe, Jeffrey M.
, p. 1355 - 1362 (2002)
Three chiral 2,5-cyclohexadienone synthons bearing different chiral auxiliaries were examined in [2+2] photoadditions with cyclopentene. Regeneration of the 'masked' double bond in the adducts resulted in the preparation of optically active 5-4-6 adducts. The enantiomeric purity of each adduct was found to be >95% using comparative 13C NMR analysis of the appropriate ketals. The asymmetry induced in the cycloaddition step of our methodology indicated that the facial selectivity was directly correlated to the degree of steric bulk of the chiral auxiliary on the synthon.
Asymmetric Total Synthesis of (-)-Guignardones A and B
Gong, Jianxian,Yan, Zhiming,Yang, Zhen,Zhao, Chunbo
, (2020)
The asymmetric total synthesis of (-)-guignardones A (2) and B (1) has been accomplished. The highly oxidized 6-oxabicyclo[3.2.1]octane core was constructed from d-quinic acid via substitution/desulfurization reaction with thiophenol to forge the bridged ring scaffold, and a Pummerer rearrangement and 1,4-addition/elimination sequence was employed to install the β-carbonyl group at the congested C-1 position. A late-stage Knoevenagel condensation-6π-electrocyclization and directed hydrogenation formed (-)-guignardone B (1), which was subjected to dehydration to furnish (-)-guignardone A (2).
Total syntheses of aminomethyl-C-dideoxyglycopyranosides and their quinamides
Gremyachinskiy, Dmitriy E.,Samoshin, Vyacheslav V.,Gross, Paul H.
, p. 6587 - 6590 (2003)
Lewis acid promoted cyclization of homoallylic alcohol 1 with acetal 2 gave 4-chloro-2-phthalimidomethyl-6-methyltetrahydropyrans. Their dehydrochlorination produced two regioisomeric dihydropyrans. Subsequent cis- and trans-dihydroxylation gave four race
Synthetic Studies of the Rubellin Natural Products: Development of a Stereoselective Strategy and Total Synthesis of (+)-Rubellin C
Gartman, Jackson A.,Tambar, Uttam K.
, p. 11237 - 11262 (2021/08/16)
This manuscript describes our studies of the class of natural products known as the rubellins, culminating in the total synthesis of (+)-rubellin C. These anthraquinone-based natural products contain a variety of stereochemical and architectural motifs, including a 6-5-6-fused ring system, 5 stereogenic centers, and a central quaternary center. Herein, we report our development of a strategy to target the stereochemically dense core and anthraquinone nucleus, including approaches such as a bifunctional allylboron and vinyl triflate reagent, an anthraquinone benzylic metalation strategy, and a late-stage anthraquinone introduction strategy. Our studies culminate in a successful route to highly functionalized anthraquinone-based natural product scaffolds and a stereoselective total synthesis of (+)-rubellin C. These strategies and outcomes will aid in synthetic planning toward anthraquinone-based natural products of high interest.
Total Synthesis of (+)-Rubellin C
Gartman, Jackson A.,Tambar, Uttam K.
supporting information, p. 9145 - 9150 (2020/08/24)
The rubellins are a family of stereochemically complex anthraquinoid heterodimers containing an unprecedented chemical scaffold. Although the rubellins have been known for over three decades, no total synthesis has been achieved since their discovery. The
