Asymmetric Total Synthesis of Shizukaol J, Trichloranoid C and Trishizukaol A

Abstract

The asymmetric total synthesis of three lindenane sesquiterpenoid oligomers, shizukaol J, trichloranoid C and trishizukaol A, has been accomplished concisely in 15, 16 and 18 longest linear steps, respectively. The expeditious construction of molecular architectures was facilitated by Nelson's catalytic asymmetric ketene–aldehyde cycloaddition, a sequence of allylic alkylation/reduction/acidic cyclization to forge a lactone, and a double aldol condensation cascade to construct the 5/6 bicyclic system. Diastereoselective nucleophilic substitution promoted by a phase transfer catalyst constructed the C11 quaternary stereogenic center, thus prompting synthetic efficacy toward shizukaol J. The synthesis of trichloranoid C and trishizukaol A was achieved after a cascade involving furanyl diene formation and a Diels–Alder reaction, as well as a one‐pot sequence involving furan oxidation and global deprotection. Furthermore, our biological evaluation revealed that two compounds exhibited unexpected toxicity against tumor cell lines.

Highly Oxidation‐Resistant Electrolyte for 4.7 V Sodium Metal Batteries Enabled by Anion/Cation Solvation Engineering

“…[10,11] Meanwhile, SMAs also suffer from the instability of electrochemical performance and enormous safety hazards due to the formation of frail solid electrolyte interphase (SEI) and uncontrollable Na dendrites. [12][13][14][15] Besides, poor thermal stability and ultrahigh moisture sensitivity are prone to produce corrosive hydrofluoric acid (HF), which further corrodes CEI/SEI and cathodes, causing rapid capacity degradation. [16,17] Therefore, developing desirable electrolytes is challenging for supporting high-voltage SMBs.…”

Chemistry and bioactivity of lindenane sesquiterpenoids and their oligomers

“…The D 4(5) double bond can be oxidized, forming the characteristic hydroxyl or peroxy-hydroxyl at C-4 or C-5 and migrating D 4(5) to D 5 (6) and D 15(4) (210)(211)(212)(213). Chlorahololides A (188), 151 C (189) 140 and spicachlorantin J (190) 152 possess a D 15 ′ (4 ′ ) double bond, and spicachlorantins E-F (191)(192), 153 sarcandrolide E (193), 107 chlorajaponilide E (194), 87 spicachlorantin G (195), 152,154 chlorasessilifol A (196), 155 fortunilides D-F (197)(198)(199), 49 chololactone B (200), 75 multistalide A (201), 141 chlomultiol B (202), 145 and sarcaglabrin B ( 203) feature an additional chiral center at C-4 ′ . 156 The migration of D 7 (11) affords a rare D 11 (13) , which is the characteristic of multistalide A (201), 141 chlomultiol B (202), 145 and sarcaglabrin B (203).…”

Recent advances in the synthesis of chiral α-tertiary aminesviatransition-metal catalysis

“…26 year, Wang et al also reported an unprecedented copper/ruthenium relay catalysed stereodivergent hydroalkylation of racemic allylic alcohols and racemic ketimine esters. 27 Merging the ruthenium-catalysed asymmetric borrowing-hydrogen reaction with a copper-catalysed asymmetric Michael addition reaction into a one-pot procedure provided a route to highly functionalized d-hydroxyesters bearing 1,4-nonadjacent stereocenters in good yields with excellent stereoselectivity under mild reaction conditions.…”