However, that preliminary study was limited to the use of phosphonium ylide reagents and commonly t-Boc (iBoc and Ac were used once) as N-protecting group. To the best of our knowledge, no further studies on the reaction conditions have been carried out. Instead, the method was applied to N-Ac aspartic, and N-Ac and N-Boc glutamic acid dialkyl esters, this time using a stabilized phosphonate ester [18]. This strategy was used later on in the synthesis of aminopeptidase A inhibitors [19]. Similarly, N-methylproline methyl ester was reacted in a similar one-pot fashion during the synthesis of nine-membered ring lactams [20]. Finally, a one- pot reduction-olefination involving an α-amino β-hydroxy ester and a phosphonium salt, both bearing free hydroxy groups, has been used in the synthesis of (−)-α-conhydrine [21].