Stereoselective synthesis of the CD-ring structure of cortistatin A (1), a novel anti-angiogenic steroidalalkaloidfrom Indonesian marine sponge, was achieved. The stereogenic tertiary carbon center bearing the isoquinoline moiety was constructed by 1,3-chiral transfer method using Johnson–Claisen rearrangement of the chiral allylic alcohol 5. Subsequent intramolecular Michael-aldol reaction afforded