300840-52-2

Upstream product

• 75-77-4 chloro-trimethyl-silane 
• 300840-51-1 14,15-dehydroerythromycin A 9-O-(1-isopropoxycyclohexyl)oxime 
• 300840-50-0 14,15-dehydroerythromycin A 9-oxime 
• 1132-95-2 1,1-diisopropoxycyclohexane 

Downstream Products

• 300840-53-3 2',4''-bis-O-trimethylsilyl-6-O-methyl-14,15-dehydroerythromycin A 9-O-(1-isopropoxycyclohexyl)oxime 
• 300840-68-0 2'-O-benzoyl-6-O-methyl-4'',11-bis(O-methanesulfonyl)-14,15-dehydroerythromycin A 
• 300840-69-1 2'-O-benzoyl-6-O-methyl-4''-O-methanesulfonyl-10,11-anhydro-14,15-dehydroerythromycin A 
• 300840-67-9 2'-O-benzoyl-6-O-methyl-14,15-dehydroerythromycin A 
• 300840-70-4 5-O-(2'-O-benzoyl-desosaminyl)-10,11-anhydro-6-O-methyl-14,15-dehydroerythronolide A 

Relevant academic research and scientific papers

Synthesis of 14,15-dehydroerythromycin A ketolides: Effects of the 13-substituent on erythromycin tautomerism

A ketolide was prepared from 14,15-dehydroerythromycin A by two different routes. The first approach involving oxidation of the 3-OH of 3-descladinosyl-14,15-dehydroerythromycin A 2′-O-acetate gave unexpectedly high levels of 3,11-double oxidation. This may be due to greater formation of the 9,12-hemiketal in 14,15-dehydroerythromycin A and concomitant exposure of the 11-OH group for oxidation. NMR studies of 14,15-dehydroerythromycin A support this hypothesis, revealing a 9:1 ratio of 9-ketone to 9,12-hemiketal in CDC13 and a 1:1 ratio in CD3OD as contrasted with the corresponding tautomer ratios of 30:1 in CDC13, and 6: 1 in CD3OD with erythromycin A. Alteration of the 13-substituent on the erythronolide A ring from ethyl to vinyl thus favors formation of the 9,12-hemiketal. A second route to the ketolides was developed based on these findings, in which the 11-OH is eliminated prior to oxidation of the 3-OH.