Abstract: The first enantioselective total synthesis of naturally occurring (+)-indolizidine 195B (bicyclic gephyrotoxin 195B) and (-)-phidine and their enantiomers has been achieved starting from 4-0-benzyl-2, 3-0-bis (methoxymethyl)-~-threitol as a single and common chiral synthon, readily available from L-tartaric acid. This synthesis establishes the absolute stereochemistry of (+)-indohidine 195B as 3S, 5S, 9S. The strategy for the synthesis of the ...