88168-76-7Relevant articles and documents
Studies Related to Thietan-2-ones. Part 2. Conversion of a Benzylpenicillin-derived Thietan-2-one into D- and L-2-Methylpenicillamines
Crilley, Martine M. L.,Stoodley, Richard J.
, p. 1127 - 1132 (2007/10/02)
(3R)- and (3S)-hept-2-en-6-yl>-3,4,4-trimethylthietan-2-ones (8b) and (9b) were isomerised to (3R)- and (3S)-3-(2-benzyloxazol-5-ylcarbonyl)amino-3,4,4-trimethylthietan-2-ones (10) and (14) by m-chlorobenzoic acid in methanol.Attempts to cleave the amide linkage of compound (10), by the action of phosphorus(V) chloride-methanol, were unrewarding.In dichloromethane containing boron trifluoride, compound (8b) was converted into (3R)-3-(2-benzyl-5-oxo-2-oxazolin-4-ylidene)amino-3,4,4-trimethylthietan-2-one (16).Ozonolysis of the lastmentioned compound in dichloromethane at -78 deg C and addition of ethanol yielded (3R)-3-(formyl)amino-3,4,4-trimethylthietan-2-one (17) and N-(ethoxycarbonyl)phenylacetamide (22a).Removal of the formyl group from compound (17) was achieved by the action of phosphorus(V) trichloride oxide-methanol to give, following addition of toluene-p-sulphonic acid, (3R)-3-amino-3,4,4-trimethylthietan-2-one toluene-p-sulphonate (4c).In boiling water, the thietanone (4c) underwent hydrolysis to give (2S)-2-amino-2,3-dimethyl-3-mercaptobutanoic acid toluene-p-sulphonate (D-2-methylpenicillamine toluene-p-sulphonate) (27b).Using a similar reaction sequence, the thietanone (9b) was transformed into L-2-methylpenicillamine toluene-p-sulphonate (28b).D-Penicillamine toluene-p-sulphonate (27a) underwent thiazolidine formation with formaldehyde more rapidly than did compound (27b).
