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

(1 S,5R,6R,7R)-( -)-7-Hydroxy-6-hydroxymethyl-2-oxabicyclo[3.3.0]octan-3-one (1) as well as the corresponding racemate rac-1 are versatile intermediates in the synthesis of natural prostaglandins2) and racemic prostaglandin analogs, such as cl~prostenol'*~) and fluprostenol'). The classical way to obtain enantiomerically pure 1 is the resolution Recently, we *) and other g r o u p~~~'~) have already advantageously used enzymatic methods for obtaining enantiomerically pure compounds of this type. The aim of this investigation has been to apply the lipase-catalyzed transesterification in organic solvents ''J') to the resolution of rac-1 into its enantiomers. As standard conditions for this investigation we have used lipases of different origin in tetrahydrofuran/triethylamine as solvent and vinyl acetate as acylating agent. We have already applied this solvent system successfully to other enantio-L''-'~) and regioselective 17) lipase-catalyzed transformations. To find out a suitable enzyme for the optical resolution of rac-1 we have tested five lipases of different origin using 1 mmol of substrate rac-1 ( Table 1).The lipase of choice for an effective separation of the enantiomers is the lipase Amano PS. After 50% conversion of the starting material rac-1 the unreacted enantiomer ent-1 can be obtained enantiomerically pure, whereas the monoacetate 2 is isolated with an e.e. of 86% (entry 3). After deacetylation of 2 the enantiomeric purity of the resulting 1 can be easily enhanced up to more than 99% by recrystallization from ethyl acetate/acetone'). The negative optical rotation of 1 proves the (lS,5R,6R,7R) configuration" of the monoacetate 2. Unreacted ent-1 shows a positive optical rotation indicating the (lR,5S,6S,7S) configuration for this enantiomer. An earlier termination of the reaction with lipase Amano PS (entries 4 and 5) yields 2 with an e.e. higher than 86%, however with a loss of chemical yield. Pancreatin shows a significantly lower enantioselectivity in this reaction (entry l), but allows the preparation of racemic monoacetate

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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.

Cited by 14 publications

References 18 publications

Biocatalytic Selective Modifications of Conventional Nucleosides, Carbocyclic Nucleosides, and C-Nucleosides

Biocatalytic Selective Modifications of Conventional Nucleosides, Carbocyclic Nucleosides, and C-Nucleosides

ChemInform Abstract: Enzymes in Organic Synthesis. Part 6. Enzyme‐Catalyzed Synthesis of ( 1S,4R)‐(‐)‐4‐Hydroxycyclopent‐2‐enyl Acetate (‐)‐(III) and Its (+)‐ Antipode ‐ An Improved Procedure Using Lipase from Mucor sp.

Enzymes in Organic Synthesis, 8. Synthesis of enantiomerically pure prostaglandin intermediates by enzymatic transesterification of (1S,5R,6R,7R)‐(±)‐7‐hydroxy‐6‐hydroxymethyl‐2‐oxabicyclo[3.3.0]octan‐3‐one

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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.

Cited by 14 publications

References 18 publications

Biocatalytic Selective Modifications of Conventional Nucleosides, Carbocyclic Nucleosides, and C-Nucleosides

Biocatalytic Selective Modifications of Conventional Nucleosides, Carbocyclic Nucleosides, and C-Nucleosides

ChemInform Abstract: Enzymes in Organic Synthesis. Part 6. Enzyme‐Catalyzed Synthesis of ( 1S,4R)‐(‐)‐4‐Hydroxycyclopent‐2‐enyl Acetate (‐)‐(III) and Its (+)‐ Antipode ‐ An Improved Procedure Using Lipase from Mucor sp.

Enzymes in Organic Synthesis, 8. Synthesis of enantiomerically pure prostaglandin intermediates by enzymatic transesterification of (1S*,5R*,6R*,7R*)‐(±)‐7‐hydroxy‐6‐hydroxymethyl‐2‐oxabicyclo[3.3.0]octan‐3‐one

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Enzymes in Organic Synthesis, 8. Synthesis of enantiomerically pure prostaglandin intermediates by enzymatic transesterification of (1S,5R,6R,7R)‐(±)‐7‐hydroxy‐6‐hydroxymethyl‐2‐oxabicyclo[3.3.0]octan‐3‐one