Diastereoselective Synthesis of All Stereoisomers of β-Methoxytyrosine, a Component of Papuamides

β-Methoxytyrosine (β-OMeTyr) is a stereoundefined component of papuamides A and B, novel cyclodepsipeptides, with anti-HIV and cytotoxic activities. For structural determination and total synthesis of papuamides, all stereoisomers of β-OMeTyr were stereoselectively prepared from (S)- and (R)-serine, respectively.