la, R= H, holomycin 2, penicillins b, R= CO, H of the carboxyl substituted derivative lb of holomycin, a substance in which this analogy is advanced one step further, and have prepared holomycin itself by decarboxylation. Our synthetic scheme was designed around two key reactions, formation of the pyrrolinone ring by cyclization of the methoxalylamine 6 to 7 and contraction of the dithioketal9 to disulfide 10a following the general method ...
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![2-(4-methoxy-phenyl)-2-methyl-6,7-dioxo-5,6,7,7a-tetrahydro-[1,3]dithiino[5,4-b]pyrrole-4-carboxylic acid methyl ester Structure](https://image.chemsrc.com/caspic/261/62698-42-4.png)
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![7-methanesulfonyloxy-2-(4-methoxy-phenyl)-2-methyl-6-oxo-5,6-dihydro-[1,3]dithiino[5,4-b]pyrrole-4-carboxylic acid methyl ester Structure](https://image.chemsrc.com/caspic/223/62698-43-5.png)
![7-(4-methoxy-benzylamino)-2-(4-methoxy-phenyl)-2-methyl-6-oxo-5,6-dihydro-[1,3]dithiino[5,4-b]pyrrole-4-carboxylic acid methyl ester Structure](https://image.chemsrc.com/caspic/185/62698-44-6.png)