A highly enantioselective hydrolysis of -3,5-diacetoxycyclopent-1-ene.

Kein Ende für Totalsynthesen von Strychnin in Sicht? Lektionen für Strategien und Methoden in der Totalsynthese

“…[40,44] 3. [51] Die stereospezifische Palladium-katalysierte Kupplung dieses enantiomerenangereicherten Zwischenprodukts mit Kohlenstoffnucleophilen war zur dieser Zeit bereits beschrieben worden. [45] Dennoch lieferte diese Hypothese ein Konzept für eine erfolgreiche Totalsynthese.…”

Preparation of a chiral synthon for an HBV inhibitor: enzymatic asymmetric hydrolysis of (1α,2β,3α)-2-(benzyloxymethyl)cyclopent-4-ene-1,3-diol diacetate and enzymatic asymmetric acetylation of (1α,2β,3α)-2-(benzyloxymethyl)cyclopent-4-ene-1,3-diol

“…28 Deardorff et al have demonstrated the hydrolysis of cis-3,5-diacetoxycyclopent-1-ene to the corresponding (3R,5S)-acetoxy-5-hydroxycyclopent-1-ene using electric eel acetylcholinesterase in 94% yield with an ee of 96%. 29 Pig liver esterase and porcine pancreatic lipase (PPL) catalyzed the enantiotopic selective hydrolysis of 2,5-bis(methoxy-carbonyl) and 2,5-bis(acetoxymethyl) meso-diester derivatives of 3,4-(isopropylidenedioxy)-tetrahydrofuran to the corresponding monoesters with an ee of 72% being demonstrated by Hultin et al 30 Transesterification of the 2,5-bis(hydroxymethyl) derivatives with trifluoroethyl laurate by PPL in ether also showed stereoselectively but in the opposite stereochemical sense from the hydrolysis of the corresponding diacetate. 31 The synthesis of 3 0 -deoxycarbacyclic nucleoside analogues has recently been demonstrated by the regioselective ring opening of the cyclopentene epoxide with lithium di-n-propylamide in ether.…”

Enzymes in Organic Synthesis. Part 6. Enzyme‐catalyzed Synthesis of (1S,4R)‐(−)‐4‐Hydroxycyclopent‐2‐enyl Acetate and its (+)‐Antipode ‐ an Improved Procedure Using Lipase from Mucor sp.

“…> 99 070. The monoacetate ent-2 was prepared by enantiose-lective hydrolysis of the meso-diacetate 3 with PPL or other lipases [21] or with cholinesterase from electric eel [22]. We found that the formation of 2 and diacetate 3 is a result of two lipase-catalyzed acylationsteps [19].…”