A facile high yield large scale methylation procedure affording 2c is reported utilizing the N-[bis(methylthio)-methylen-protected derivative 4a as an intermediate. The optical resolution of racemic 2c is described leading to (S)-2b. In addition the thiolactone 2c undergoes oxidative ring opening by bromine to the corresponding sulphonic acid 5.
A facile high yield large scale methylation procedure affording 2c is reported utilizing the N-[bis(methylthio)-methylen-protected derivative 4a as an intermediate. The optical resolution of racemic 2c is described leading to (S)-2b. In addition the thiolactone 2c undergoes oxidative ring opening by bromine to the corresponding sulphonic acid 5.