Total synthesis of (4R,5S)-melithiazol C and (3R,4S)-cystothiazole E

A Wittig reaction between (+)-chiral aldehyde (4R,5R)-3 and the phosphoranylide derived from the mono-thiazole-type phosphonium iodide [(+/-)-10] using lithium bis(trimethylsilyl)amide afforded the (+)-melithiazol C (1), whose spectral data were identical with those of the natural product [(+)-1]. Moreover, the Julia's coupling of aldehyde (21) and the bithiazole-type sulfone (5) followed by the consecutive deprotection and Dess-Martin oxidation gave the (+)-cystothiazole E (2), whose spectral data were identical with those of the natural product [(+)-2].