81902-54-7

Upstream product

• 81902-60-5 t-butyl N-(2,4-dimethoxybenzyl)glycinate 
• 20839-79-6 (2,4-dimethoxy-benzylamino)-acetic acid 
• 80829-72-7 (+/-)-<3α(S^*),4β>-t-butyl-1-(2,4-dimethoxybenzyl)-3-(1-hydroxyethyl)-2-azetidinone-4-carboxylate 
• 87542-16-3 (2RS,3RS)-1-(2,4-dimethoxybenzyl)-3-(2-methyl-1,3-dioxolan-2-yl)-4-oxoazetidine-2-carboxylic acid 
• 115855-61-3 (2S,3S)-1-(2,4-Dimethoxy-benzyl)-3-(2-methyl-[1,3]dioxolan-2-yl)-4-oxo-azetidine-2-carboxylic acid benzhydryl ester 
• 85621-92-7 Ethyl (2RS,3SR)-1-(2,4-Dimethoxybenzyl)-3-(2-methyl-1,3-dioxolan-2-yl)-4-oxoazetidine-2-carboxylate 
• 85621-92-7 ethyl 1-(2,4-dimethoxybenzyl)-3-(2-methyl-1,3-dioxolan-2-yl)-4-oxoazetidinecarboxylate 
• 85486-88-0 (+/-)-<3α(S^*),4β>-t-butyl-1-(2,4-dimethoxybenzyl)-3-(1-t-butoxycarbonylcarboxyethyl)-2-azetidinone-4-carboxylate 
• 81902-68-3 (2S,3R)-N-(2,4-dimethoxybenzyl)-N-(t-butoxycarbonylmethyl)-2,3-epoxybutyramide 
• 81902-59-2 (2S,3R)-N-(2,4-dimethoxybenzyl)-N-(t-butoxycarbonylmethyl)-2-bromo-3-hydroxybutyramide 
• 20781-21-9 2,4-dimethoxybenzylamine hydrochloride 
• 613-45-6 2,4-Dimethoxybenzaldehyde 
• 81902-50-3 (2R,3R)-N-2,4-dimethoxybenzyl-N-bis(ethoxycarbonyl)methyl-2-bromo-3-acetoxybutylamide 
• 81902-51-4 <3S(R)>-1-(2,4-dimethoxybenzyl)-3-(1-acetoxyethyl)-4,4-bis(ethoxycarbonyl)-2-azetidinone 

Downstream Products

• 81902-57-0 <3S-<3α(S^*),4β>>-1-(2,4-dimethoxybenzyl)-3-(1-t-butyldimethylsilyloxyethyl)-2-azetidinone-4-carboxylic acid 
• 81902-58-1 <3S-<3α(S^*),4β>>-1-(2,4-dimethoxybenzyl)-3-(1-t-butyldimethylsilyloxyethyl)-2-azetidinone-4-carboxylic acid chloride 
• 82008-55-7 <3S-<3α(S^*),4β>>-1-(2,4-dimethoxybenzyl)-3-(1-t-butyldimethylsilyloxyethyl)-4-acetyl-2-azetidinone 
• 87392-18-5 <3S-<3α(S^*),4β>>-benzyl<3-(1-t-butyldimethylsilyloxyethyl)-2-azetidinone-4-yl>acetate 
• 81902-65-0 <3S-<3α(S^*),4β>>-benzyl<1-(2,4-dimethoxybenzyl)-3-(1-t-butyldimethylsilyloxyethyl)-2-azetidinone-4-yl>acetate 
• 92685-93-3 <3R-<3α(R^*),4β>>-1-(2,4-dimethoxybenzyl)-3-(1-t-butyldimethylsilyloxyethyl)-4-acetoxy-2-azetidinone 
• 92685-97-7 [(2R,3S)-3-[(R)-1-(tert-Butyl-dimethyl-silanyloxy)-ethyl]-1-(2,4-dimethoxy-benzyl)-4-oxo-azetidin-2-yl]-acetyl chloride 
• 92685-92-2 <3S-<3α(S^*),4β>>-<1-(2,4-dimethoxybenzyl)-3-(1-t-butyldimethylsilyloxyethyl)-2-azetidinone-4-yl>acetic acid 
• 92685-98-8 <3S-<3α(S^*),4β>>-1-(2,4-dimethoxybenzyl)-3-(1-t-butyldimethylsilyloxyethyl)-4-(2-oxo-3-chloropropyl)-2-azetidinone 
• 81902-67-2 [(2R,3S)-3-[(R)-1-(tert-Butyl-dimethyl-silanyloxy)-ethyl]-1-(2,4-dimethoxy-benzyl)-4-oxo-azetidin-2-yl]-acetic acid methyl ester 
• 81902-64-9 <3S-<3α(S^*),4β>>-1-(2,4-dimethoxybenzyl)-3-(1-t-butyldimethylsilyloxyethyl)-4-diazoacetyl-2-azetidinone 
• 78477-86-8 (3S,4R)-3-<(R)-1-hydroxyethyl>-4-<(benzyloxycarbonyl)methyl>-2-azetidinone 

Relevant academic research and scientific papers

Simple and Condensed β-Lactams. Part 9. Elaboration of the 3-(1-Hydroxyethyl) Side Chains of Potential Intermediates of Carbapenem Antibiotics via the 2-Methyl-1,3-dioxolan-2-yl Group

Deketalization of the trans compounds methyl and ethyl (2RS,3RS)-1-(2,4-dimethoxybenzyl)-3-(2-methyl-1,3-dioxolan-2-yl)-4-oxoazetidine-2-carboxylates 5b and 5c, and of the cis isomer (6b) of the latter leads to 85:15 mixtures of the trans- and cis-compounds methyl (2RS,3RS)- and (2RS,3SR)-3-acetyl-1-(2,4-dimethoxybenzyl)-4-oxoazetidine-2-carboxylate (7a) and (8a), respectively of the corresponding ethyl esters (7b) and (8b).Sodium borohydride reduction of the mixture of the trans- and cis-esters (7b) and (8b) gives a mixture of the 1'-epimeric trans-compounds ethyl(2RS,3RS)-1-(2,4-dimethoxybenzyl)-3--4-oxazetidine-2-carboxylate (9b) and (10b).Similar mixtures of 1'-epimeric compounds of the types (9) and (10), carrying a variety of substituents attached to position 2 of their azetidine rings were obtained by successive deketalization and reduction of the corresponding trans-(5) and cis-(6) compounds or their mixtures, as well as by other methods.Ring closure of a mixture of the pair of the 1'-epimeric trans-compounds p-nitrobenzyl 2-diazo-4--4-oxo-azetidin-2-yl>-3-oxobutanoates (9n) and (10n) gave a mixture of the 1'-epimeric compounds p-nitrobenzyl 6--2,7-dioxo-(3RS,5RS,6SR)-carbapenam-3-carboxylates (11) and (12) which was converted into a mixture (13) of the 1'-epimeric bis-protected thienamycin analogues p-nitrobenzyl 2-(2-formylaminoethylthio)-6--7-oxo-(5RS,6SR)-carbapen-2-em-3-carboxylates.

STEREOSPECIFIC SYNTHESIS OF CHIRAL PRECURSORS OF THIENAMYCIN FROM L-THREONINE

L-Threonine was transformed, stereospecifically, to a versatile β-lactam (5a) in 3 steps.This β-lactam was further converted to a key intermediate (25) for the synthesis of thienamycin and its biologically active analogues.Furthermore, the compound 5a was changed to iodides (18 and 23), cyanides (19 and 24), chloromethylketone (26) and aldehydes (30 and 31) which appear to have a latent potential as precursors for the syntheses of the carbapenems.

STEREOSPECIFIC SYNTHESIS OF RACEMIC INTERMEDIATES OF THE PENEMS AND THE CARBAPENEMS FROM TRANS-CROTONIC ACID

Stereocontrolled syntheses of two (+)-3-(1-t-butyldimethylsilyloxyethyl)-4-acetoxy-2-azetidinones (cis-10 and trans-10), which are key intermediates for the penems and the carbapenems, from trans-crotonic acid are reported.