CS268841B2 - Method of optically active(-)-oxabicyclo/3,3,0/octanoles production - Google Patents

Abstract

Process for the manufacture of (-)-oxabicyclo[3.3.0]octanolones of formula (-)-I, where R is hydrogen or the residue (a), in which R1 has the notation of a hydrogen, alkyl with 1-7 C atoms, or phenyl. The process is characterized in that a racemic oxabicyclo[3.3.0]-octanolone-acylate of formula (+/-)-II, where R1 has the above notation, is subjected to a stereo-specific acylate hydrolysis and the (-)-I (R = (a)) is separated from the saponified (+)-I (R = H) or the saponified (-)-I (R = H) is separated from the unsaponified (+)-II.

Description

CS 26SS41 32

The present invention also relates to a process for the ether-specific hydrolysis of racemic acyl 7-α-acyloxy-6β-hydroxymethyl-2-oxabicyclo [2.3.1] octatan-3-ones by enzymes to form corresponding optically active alcohols, i.e. optically active (-) - oxabicyclo- ^ 3 »3 oJ oktanolonů _e.

The process according to the invention is particularly suitable for the production of optically active (-) - oxablicyclo [з »3.о] octenolones of the general formula (-) - X

in which·

R represents a hydrogen atom or an unsaturated group of the formula

přičeaž

R | a hydrogen atom is an alkyl group of 1 to 7 carbon atoms or a phenyl group. This process consists in the formation of a racsaic oxebicyclo [zinc] octanone acylate of the general formula (♦).

in which·

R | as described above, it undergoes enzymatically ether-specific hydrolysis of the acylate. whereupon a compound of formula (-) - wherein R is a group of formula

CS 268 * 41 B2

wherein the aforementioned meaning is not. separated from the saponified compound of formula (+) - I. wherein R denotes atoa hydrogen, or a sub-saponified compound of formula (-) - in which R denotes one hundred hydrogen, separates from the non-saponifiable compound of formula (+) - 11.

If R is an alkyl group of 1 to 7 carbon atoms, then the ethyl group is ethyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl. a group, an n-pentyl group, an isopentyl group, an e-pentyl group, a neopentyl group. n-hexyl, isohexyl, n-heptyl, ioheptyl, etc.

Compounds of formula (-) - 1 are valuable Intermediates in the synthesis of physiologically valuable analogs of prostsgginine · proetscycline (cf., for example, O. Lindra, R. Bindra. Frostaglandin Synthseis. Acadenic Prese. New York 1977 and C. Szantay. L. Novak. Synthesis of Prostaglandins, Akadesiai Kládo, Budapest, 1978).

For the synthesis of compounds which are analogous to the natural products, esters of this series of enantiomers are required,

Although the asynthesis of asymmetric compounds is known, it is advantageous in the technical manufacture of introducing optical activity via the ratcheting of the intermediate of the aforementioned formula (+) - 3. In this case, the following reaction steps are required to influence the lecton on the hydroxyalkyleeline.

2, Conversion to an enantiomer of diastereoaernal salts, for example using d-phenylethylaine.

3, Crystallizscs in order to obtain diastereomeric pure salt.

4, Conversion of the salt to an optically active lactone of formula (-) - 3.

5, Further Reaction to Form an Optically Active Intermediate of Formula (-) - I.

Due to the tendency of the hydroxyalkyleelines to re-form the lactone. before it would be possible to purify by optical means, as well as due to loss of yield in crystallization. the aforementioned procedure did not work.

HIM

CCOH

racemate separation

---> some degrees

[(-) - 2]

In the process of the present invention, the separation is carried out at the racemic step of the enzymatic saponification of the acyloxy-6β-hydroxymethyl-2 * oxsbicyclo [3.3.1.0] actan-3-ones of the formula resulting in a mixture of products from which the desired compounds of formula (-) - X can either be extracted or from the aqueous phase ·

The starting materials can be prepared according to the process described in British Patent Specification No. 1,579,464. The use of optically selective esters of the formula (-) - I in which R represents a group of

obtained by the process according to the invention »as intermediates for the production of pharmacologically valuable analogues of prostaglandin and prostacyclin» follows from the references cited above.

The optically active diol of the formula (-) - I also obtained in which R represents a hydrogen atom can also be used, in particular, when the primary hydroxyl group is first protected in a subsequent synthesis and the secondary hydroxyl group can remain free. Synthesis of carbacycline-ai-products as described in EP 41 661 as enzymes are preferably used as enzymes for the process according to the invention. Subtiliain * from Bscillus subtilis (manufactured by Boehrlngsr Mannheim)

Lipase Sclerotlnia * (manufactured by Nagase)

Alksline Proteinase (manufactured by Nagase) protease from Bacillus subtilis * Alcslsee T * (manufactured by NOVO)

These enzymes can be used in both the suspended and immobilized state (e.g., in the form of cyanogen bromide-activated eephsrosy (BrCN) or on oxlacrylic beads or in some other immobilized form)

The optically active oxabicyclooctanolone derivatives of formula (-) - »which can be prepared by the process of the invention are valuable intermediates for the synthesis of pharmacologically active prosteglsndins and prostacyclins. to the optically active diol of the general formula (♦) - »in which R represents a hydrogen atom» the racemate component of the formula (+) - II used corresponding to its absolute configuration of the natural prostacyclins PGO?

CS 26SS41 B2

and after separation of the diol and e may be used to synthesize prostecycline analogs and natural configuration.

Other enzymes re-saponify from both components of the used racamate of formula (♦) -II the form and natural configuration to the diol of formula (-) - I in which R is atoa hydrogen, while * an opaque enantiomar and a configuration that does not match the it remains unsaponified, in this case ee diol uses proetacyclines to synthesize PGD analogues? ·

The process according to the invention is otherwise carried out under conditions known per se which are known for enzymatic reactions. The course of the enzymatic conversion is monitored by analysis of continuously sampled samples. High performance liquid chromatography or rapid analysis by thin layer chromatography (analytical methods) are suitable. siliksgsl manufactured by Herek, Darmstadt · developed with a 1: 1 mixture of methylene chloride and acetone and detection (coloring) with sulfuric cyeeline).

When 50% of the racemic substrate used is reacted, the reaction is stopped and the reaction mixture is worked up.

The process according to the invention is particularly suitable for athereoepecific saponification of the following intermediate stages of proetaglendinut

O

i b - what

The following examples serve to illustrate the process of the invention. However, these examples did not limit the scope of the invention to any extent.

Example 1

300 g of (7) -7-N-benzoyloxy-6-hydroxy-2-oxabicyclo [3.3.0] oct-3-one is dissolved in 9 · 1 ethanol and the solution is added and 750 g of Alkaline Proteinese * (product) is added. firay Nagaae) in 100 · 1.0 0.1M phosphate buffer solution at pH 7. Shake the reaction solution at 2 ° C on a rotary shaker # until the reaction is followed by analyzing the sampled # # After 19 hours reaction time, 50% of the used The obtained aaa and ae now extracts three times with 50 [mu] l of ethyl ethyl isobutyl ketone each while unreacted benzoate is transferred to the β-ethyl isobutyl ketone phase, while the saponified compound remains in the aqueous phase #

The methyl isobutyl ketone extracts are combined and concentrated to dryness at an extreme pressure. The residual residue was recrystallized from acetone. 135 g of (-) - 7C-benzoyloxy-6H-hydrohydro-2-oxabicyclo [3.3.0] octane-3-one having a melting point of 116 DEG-117 DEG C. were obtained. optical rotation - -80.5 ⁰ (c 1.050 in chloroform) ·

Example 2

300 g (♦) -7o <benzoyloxy-6-2--hydroxyaathyl oxebicyklo [3,3 ₉ octan-3-one are suspended in 100 «1 И 0.1 phosphate buffer pH 7, the resulting suspension к and add 750 g of Subsilisin from Bacillus subtilis (manufactured by Boehringsr, Mannhei) and ae eeogenize with high speed agitator (Ultra-Turrax). The suspension is shaken for 16 hours at 28 ° C on a rotary shaker. 50% of the racaic substrate used is contaminated. Saesa is now concentrated to a vacuum under a water pump vacuum, the remainder is extracted three times with aathanolea. the combined ethanolic eluates were re-evaporated to dryness and the residue chromatographed over silica gel (using methylene chloride and acetone in 66:33 as a reagent) # The eluting first fraction 1 contained 122 g of (-) - 7'-benzoyloxy-6/5 -hydroxyaethyl-2-oxabicyclo £ 3.3 octan-3-one, mp 114-116 ° C, the optical táčivoati _Q ⁰ -82.3 (c 1.015 in methanol, to ·).

Example 3

Under the conditions described in Example 2, 300 g of (+) - 7 &apos; -benzoyloxy-6,11-hydroxy-ethyl-2-oxabicyclo [3.3.0] octan-3-one in phosphate buffer at pH 7 is treated with 750 g. Sclerotine lipase (manufactured by firay Nagase) for 64 hours at 28 ° C # 115 g of (•) -7P <benzoyloxy-6/3-hydroxyaethyl-2-oxabicyclo / Ъ are recovered after separation of the saturated anantioamer with unnatural configuration by column chromatography. 115 DEG-116 DEG C. and an optical rotation of [.alpha.] _D -79.0 DEG (c = 1.02 in ethanol).

Example 4

Under the conditions described in Example 2, 300 g of (R) -7 N -benzoyloxy-6 H -hydroxyethyl-2-oxabicyclo [3.3.0] octan-3-one is hydrolyzed in phosphate buffer at pH 7 of action and 750 g. Alcalases T (firay NOVO product) for 40 hours at 28 ° C. After separation by reaction and column chromatography, 142 g of (-) - 7O-benzoyloxy-6,5-hydroxy-ethyl-2-oxabicyclo [3.3.1] octan-3-one having a melting point of 112 DEG-114 DEG C. and optical rotation is obtained. [Α] _D - -77.0 ^° (c 1.005 in ethanol).

Example 5

Under the conditions described in Example 2 and 300 g of (*) - 7-L-benzoyloxy-6/4-hydroxy-ethyl-2-oxabicyclo [2,3-b] octan-3-one in a phosphate buffer of pH 7 acts 750 ag of protease from Bacillus aubtilia for 15 hours at 28 ° C. After separation by reaction and column chromatography, 119 ag of 1- (7-benzoyloxy-6/3-hydroxy-ethyl-2-oxabicyclo-3-ol, octane-3) was obtained. -one, m.p. 113-115 ° C and optical otáčivoeti _Q ⁰ -78.9 (c 1.025 in methanol, to ·) ·

Claims (2)

MEDMET OF THE INVENTION l _v A method for producing optically active (-) - oxsblcyclo [з * 3, о] pattern · (-) ·! octsnolone OR [(-) - l) in which · R is hydrogen or a group of the formula wherein R Marking ato · · hydrogen alkyl having 1-7 C atoms or a phenyl group wherein * · ·· ее those that racsaický oxsbicyklo- ^ 3 »3-oJ oktenolon scylét community» _(Joint formula (♦) · !! In which it has the above-mentioned meaning. subjected to enzymatically stareoapsclic hydrolysis of the acylate, whereupon a compound of formula (-) - I in which R is a group of formula CO separates from a saponified compound of formula (+) - I in which R denotes ato · hydrogen, or as separates a saponified compound of formula (-) - I in which R denotes ato · hydrogen from an unsubstituted compound of formula (+) -11. 2. The method according to claim 1, wherein the enzyme is Subtiliain from Becillus aubtilis, Lipase Sclerotinis, Alkalina Proteinaee, proteases from Baclllus aubtllis or Alcalase T.