Pseudodistomin C(1), a piperidine alkaloid isolated from the Okinawan tunicate Pseudodistoma kanako, has been synthesized from D-serine to provide a further unambiguous evidence for the whole structure of 1 whic possessed the opposite absolute configurations at the C-4 and C-5 chiral centers from those of pseudodistomins A(2) and B(3) obtained from the same tunicate.