Imidazole → HCID 70455674, compound

Participants

Reaction Steps

In a manner analogous to that described in Examples (1ba) to (1bc), by reaction of (3S,5R,6R)-2,2-dimethyl-6-[(1R)-1-hydroxyethyl]-penam-3-carboxylic acid benzyl ester 1,1-dioxide (German Offenlegungsschrift No. 3039504) with tert.-butyldimethylchlorosilane and imidazole, (3S,5R,6R)-2,2-dimethyl-6-[(1R)-1-(tert.-butyl-dimethyl-silyloxy)-ethyl]-penam-3-carboxylic acid benzyl ester 1,1-dioxide [IR (methylene chloride): 3.42; 5.56; 5.63μ] is obtained, which is treated with DBU and then with DBU/methyl iodide. The resulting 2-[(3S,4R)-3-((1R)-1-(tert.-butyl-dimethyl-silyloxy)-ethyl)-4-methylsulphonyl-2-oxoazetidin-1-yl]-3-methyl-2-butenoic acid benzyl ester [IR (methylene chloride): 5.63; 5.80; 6.15μ] yields the desired product when ozonolised and subsequently treated with methanol.

Provenance & Evidence