... SH NH2 (I) HCl or HgCU S NH OH- N i DCC CO CO / \/ \ CH2-CH NS II CH-CH2 [ C02H CO (П) _l AC20 S NH \ / CO (IV) *' Partly presented at the 15th Annual Meeting of the Chemical Society of Japan ... 3 Present address : Institute for Food Chemistry, Kita-ku ... Japan, Pure- Chem. ...