Synthesis of optically active 6-amino-2-cycloheptenone as a convenient chiral building block for the preparation of 6-alkyl-2-cycloheptenone

Metal-Mediated Synthesis of Medium-Sized Rings

“…Sato utilized the free radical ring expansion of cyclopropanol 297 with ferric chloride followed by elimination with sodium acetate to give optically active 6-amino-2-cycloheptenones 298 (Scheme ) …”

Synthesis of Organotitanium Complexes from Alkenes and Alkynes and Their Synthetic Applications

“…The tandem INAS−ring enlargement reaction described above was also applied for synthesizing chiral 6-amino-2-cycloheptenone, which can be used as a building block for preparation of optically active 6-alkyl-2-cycloheptenone (eq 120) …”

Copper‐mediated Diastereoselective Conjugate Addition and Allylic Substitution Reactions

“…Most of the useful auxiliaries are chiral amine or alcohol derivatives readily available from the chiral pool, and most of them possess rigid cyclic or bicyclic structures to allow efficient differentiation of the two competing diastereomorphic transition states. In some cases, additional rigidity was achieved with the aid of an external chelating Lewis acid (entries 6,10,12). In certain cases, however, acyclic auxiliaries may also be useful (see entry 15).…”

“…Thus, starting Scheme 6.27. Auxiliary-controlled stereoselective cuprate addition as the key step for the construction of both diastereomeric forms of [5][6][7][8][9][10][11][12][13] C]-leucine 144.…”