Solution and Solid Phase Synthesis of Unusual a-Amino Acids From

4.1 .4.2 Enzymatic Metho& ................................................................................. 143
4.1.4.3 Catalytic Hydrogenaîion .................................... .................................. 145
4.1.4.4 anion Chemistry (Including Pyroglutamic Acid) ................................ 148
4.1.4.5 Other Methods for the Synîhesis of ~Substituted Glutumic .................... 152
4.2 Resuits and Discussion: Syntbesis of @ubstituted Glutamates ......................... 154
4.2.1 Methylation of Cbz-Glu(0Me)OBO 4.69: Optimization and Detemination
of Diastereoselectivity .................................................................................... 154
4.2.2 Addition of Other AMcylating Agents to Cbz-Glu(0Me)OBO 4.69 ................... 167
4.2.3 Aldol Reaction of Cbz-Glu(0Me)OBO 4.69 .................................................. 168
4.2.4 y Hydroxylation of Cbz-Glu(OMe)OBO 4.69 .............................. . ......... 169
4.2.5 yAminatiun of Cbz-Glu(OMe)OBO 4.69 ...................................................... 175
4.2.6 Mlogenation of Cbz-Glu(OMe)OBO 4.69 ........................ . .............. 177
4.2.7 ycarboxylation of Cbz-Glu(0Me)OBO 4.69 ................................................. 179
4.2.8 Claisen Condensation of Cbz-Glu(OMe)OBO 4.69 ....................................... 179
4.2.9 Deprotection of ysubstituted Glutantic Acids ................................................. 181
4.2.10 Discussion of the Stereoselectivity of Electrophilic addition tu the
Cbz-Glu(0Me)OBO ester 4.69 Enolate .......................................................... 183
4.3 Summary .............................................................................................................. 185
4.4 ExpeFimentd Results .............................................................................................. 187
4.5 References .............................................................................................................. 239
Chapter Five
Stereoselective Synthesis of substitutc cd Asparîic Acids
5.1 Introduction ............................................................................................................. 249
5.1.1 Isolation ....................................................................................................... 249
5.1.2 Bblugical Activity ......................................................................................... 250
5.1.3 Synthesis of #3-Substituted Aspartic Aciàs ....................................................... 251
5.1.3.1 Synthesis of PSubstituted Aspartic Acids: General Racemic ................. 251
5.1.4 Synthesir of Optically Active PSubstituted Aspartic Acids ............................. 253