Hydroxylation of ansamitocin P-3.

Abstract
Ansamitocin P-3 was converted into 15-hydroxyansamitocin P-3 (PHO-3), C32H43ClN2O10, and 15-epi-15-hydroxyansamitocin P-3 (epi-PHO-3), C32H43ClN2O10, by actinomycetes. PHO-3 was identical to deacetylmaytanbutacine and epi-PHO-3 was a new compound. The configuration at C15 was elucidated as R for PHO-3 and S for epi-PHO-3 on the basis of their physicochemical properties and X-ray analysis of epi-PHO-3.