130697-55-1

Upstream product

• 130632-16-5 Benzyloxy-acetic acid (1R,2S)-2-methylamino-1-phenyl-propyl ester 
• 120419-97-8 (E)-N-benzylidene-1,1,1-trimethylsilanamine 
• 19810-31-2 Benzyloxyacetyl chloride 
• 15484-91-0 (Z)-N-(benzylidene)-4-ethoxyphenylamine 
• 100-52-7 benzaldehyde 
• 17599-61-0 N-benzylidene-1,1,1-trimethylsilanamine 

Relevant academic research and scientific papers

Enantioselective hydrolysis of 3,4-disubstituted β-lactams. An efficient enzymatic method for the preparation of a key Taxol side-chain intermediate

3,4-Disubstituted β-lactams 3-benzyloxy-4-(4-chlorophenyl)azetidin-2-one [(3S?,4R?)-(±)-1], 3-benzyloxy-4-phenylazetidin-2-one [(3S?,4R?)-(±)-2] and 4-(4-chlorophenyl)-3-phenoxyazetidin-2-one [(3S?,4R?)-(±)-3] were resolved through immobilized CAL-B-catalysed ring-cleavage reactions. Excellent enantioselectivities (E > 200) were obtained for (3S?,4R?)-(±)-1 and (3S?,4R?)-(±)-2 when the reactions were performed with added H2O as nucleophile in tert-butyl methyl ether at 70 °C, whereas only moderate E (12) was achieved for (3S?,4R?)-(±)-3 under the same conditions but in diisopropyl ether. The resulting ring-opened β-amino acids [(2R,3S)-4 (ee > 98%), (2R,3S)-5 (ee > 98%) and (2R,3S)-6 (ee = 50%)] and the unreacted β-lactams [(3S,4R)-1-3] (ee > 98%) could be easily separated.

New and efficient approaches to the semisynthesis of taxol and its C-13 side chain analogs by means of β-lactam synthon method

Highly efficient chiral ester enolate-imine condensation giving 3-hydroxy-4-aryl-β-lactams with excellent enantiomeric purity is successfully applied to the asymmetric synthesis of the enantiomerically pure taxol C-13 side chain, N-benzoyl-(2R,3S)-3-phenyl-isoserine and its analogs. (3R,4S)-N-benzoyl-3-(1-ethoxyethoxy)-4-phenyl-2-azetidinone readily derived from the 3-hydroxy-4-phenyl-β-lactam is coupled with protected baccatin IIIs, followed by deprotection to give optically pure taxol and 10-deacetyl-7,10-bis(Troc)-taxol in good yields. Fully assigned 1H, 13C, and 2D (COSY and HETCOR) NMR spectra of taxol thus synthesized are shown and discussed.

ASYMMETRIC SYNTHESIS OF β-LACTAMS BY CHIRAL ESTER ENOLATE-IMINE CONDENSATION

Asymmetric cyclocondensation of N,N-bis(silyl)glycinates bearing chiral ester moieties with aldimines is found to proceed with extremely high enantioselectivity to give the corresponding chiral β-lactams in good to high yields.It is found that the E/Z-geometry of the chiral ester-enolate is responsible for cis/trans stereochemistry of the β-lactam formed.Effects of various chiral auxiliaries in the ester-enolates on the enantioselectivity of the reactions are examined.