- Chemoenzymatic Route for the Synthesis of (S)-Moprolol, a Potential β-Blocker
-
A biocatalytic route for the synthesis of a potential β-blocker, (S)-moprolol is reported here. Enantiopure synthesis of moprolol is mainly dependent on the chiral intermediate, 3-(2-methoxyphenoxy)-propane-1,2-diol. Various commercial lipases were screened for the enantioselective resolution of (RS)-3-(2-methoxyphenoxy)propane-1,2-diol to produce the desired enantiomer. Among them, Aspergillus Niger lipase (ANL) was selected on the basis of both stereo- and regioselectivity. The optimized values of various reaction parameters were determined such as enzyme (15 mg/mL), substrate concentration (10 mM), organic solvent (toluene), reaction temperature (30 °C), and time (18 h).The optimized conditions led to achieving >49% yield with high enantiomeric excess of (S)-3-(2-methoxyphenoxy)propane-1,2-diol. The lipase-mediated catalysis showed regioselective acylation with dual stereoselectivity. Further, the enantiopure intermediate was used for the synthesis of (S)-moprolol, which afforded the desired β-blocker. Chirality 28:313-318, 2016.
- Ghosh, Saptarshi,Bhaumik, Jayeeta,Banoth, Linga,Banesh, Sooram,Banerjee, Uttam Chand
-
p. 313 - 318
(2016/03/19)
-
- Discriminative Glycosylation of 3-(Aryloxy)propane-1,2-diols by Choice of a Glycosyl Donor
-
Regioselective glycosylation of rac-guaifenesin (1A) with various glycosyl donors viz., β-D-glucosepentaacetate (2), pyridyl 2,3,4,6-O-tetra-O-benzyl- 1-thio-β-D-galactopyranoside (9), 1-O-acetyl-2,3,5-tri-O-benzoyl-α/ β-D-ribo- (13) and xylofuranoside (17) is reported. Glycosyl donors 2, 13 and 17 bearing ester protecting groups is reported to exhibit high regioselectivity to form the corresponding diastereomeric mixture of 1-O-glycosylated guaifenesin derivatives 3A, 14A and 18A, respectively; formation of diglycosylated derivatives 5A, 15A and 19A is not observed. While no such selectivity is observed when the donor 9 bearing ether protecting groups is used in the coupling reaction with 1A, resulting in the formation of digalactosylated derivatives 10A. That the regioselectivity is not dependent upon substituents present on the aromatic ring is shown by coupling IB with 2 to isolate 1-O-glycosylated derivative 3B; formation of diglycosylated derivative 5B was not observed. Applicability of this finding is shown by preparation of enantiopure guaifenesin [(R)-1 (98% ee) and (S)-1 (98% ee)] by separation of their corresponding diastereomers (R)-3 and (S)-3, respectively.
- Mereyala, Hari Babu,Mamidyala, Sreeman Kumar,Chigurapati, Krishna Prasad,Srinivasa, Sastri R.
-
p. 2378 - 2384
(2007/10/03)
-
- Kinetic resolution of acyclic 1,2-diols using a sequential lipase- catalyzed transesterification in organic solvents
-
A method for the kinetic resolution of 3-(aryloxy)-1,2-propanediols rac- 1a-n without additional protection-deprotection steps using a lipase- catalyzed sequential transesterification with lipase amano PS has been developed. In the first step of this one-pot procedure the racemic 1,2-diols are acylated regioselectively at the primary hydroxy group without enantioselection. The subsequent acylation at the secondary hydroxy group of the formed primary monoacetate is responsible for high enantioselection. The enantioselectivity of this transformation depends significantly on the substitution pattern of the aryl ring and the organic solvent used. 3- (Aryloxy)-1,2-propanediols with substituents in the para-position show a much higher enantioselectivity than the corresponding derivatives with ortho- substituents. Among other substrates, the pharmaceuticals Mephenesin, Guaifenesin, and Chlorphenesin have been resolved. The replacement of the aryloxy by an alkyl substituent causes a dramatic decrease of enantioselectivity.
- Theil,Weidner,Ballschuh,Kunath,Schick
-
p. 388 - 393
(2007/10/02)
-
- Kinetic resolution of aliphatic 1,2-diols by a lipase-catalyzed sequential acetylation
-
The kinetic resolution of 13 racemic aliphatic 1,2-diols (rac-1a-m) by means of a lipase-catalyzed sequential acetylation was investigated. The enantioselectivity of the 3-aryloxy-propane-1,2-diols rac-1a-k depends on the substitution pattern at the aryl ring.
- Theil, Fritz,Weidner, Judith,Ballschuh, Sibylle,Kunath, Annamarie,Schick, Hans
-
p. 305 - 306
(2007/10/02)
-