Total synthesis and stereochemical reassignment of (+)-dolastatin 19.
[reaction: see text] A revised configurational assignment for the cytotoxic marine macrolide dolastatin 19 is proposed and validated by total synthesis. Key features of the route include an asymmetric vinylogous aldol reaction to install the isolated C13 stereocenter and (E)-trisubstituted alkene, two sequential 1,4-syn boron-mediated aldol reactions, and a Mukaiyama glycosylation to append the l-rhamnose-derived pyranoside.
Paterson
Ian
I
University Chemical Laboratory, Cambridge, UK. jp100@cam.ac.uk
Findlay
Alison D
AD
Florence
Gordon J
GJ