This invention concerns a process to convert a hydroxyl group (bold in R.sub.3C--OH) in a tigliane-type compound to a hydrogen (bold in R.sub.3C--H) to obtain deoxytigliane-type compounds or structural or functional analogs thereof. The process has wide application particularly to produce specific biologically active compounds in quantity for use as pharmaceuticals. In particular the process can be used to convert phorbol to a 12-deoxytigliane (prostrating which is a therapeutic lead for the treatment of AIDS. New compositions of matter are also disclosed.