I would like to modify the suggestions you have already received.
Please, note that the final deprotection of a single Acm-group with
Hg(OAc)2 also implies a post-treatment with H2S, mercaptoethanol or the
like. All these will remove disulfide bridge as well.
Tributylphosphine which is used to remove t-BuS- group is also an
excellent disulfide reducing agent.
Therefore, t-Bu- and MBzl- groups and strong acid deprotection seem to be
the best choices.
Good luck.
Igor Rodionov
Laboratory Of Peptide Chemistry
Branch of Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry
Pushchino, Moscow Region
142292, Russian Federation
E-mail: <rodionov@fibkh.serpukhov.su> or <Igor_Rodionov@iname.com>
Fax: (0967)-79-05-27
Phones: (0967) 73 54 42; private: (0967) 73 58 26