Chiral acylnitroso dienophiles 14, which were obtained from L-proline and from D-mandelic acid, reacted with cyclohexa-1,3-diene to give the expected diastereoisomers 15 and 16 (Scheme 2 and Table 1). The d.e. values for these Diels-Alder reactions were moderate; they are related to the molecular stiffness of the dienophiles. The absolute configuration of the major cycloadducts was interpreted in terms
Cyclopentadiene nitroso adducts 1a and ent-1a were synthesised in good yields and good enantiomeric excess from chiral chloro-nitroso derivatives 4 and 5 in the d-mannose and d-ribose series, respectively. The thermal racemisation of these adducts occurred below room temperature. Some other chiral Diels–Alder nitroso adducts were prepared in the d-mandelic, l-prolinol and d-O-methylprolinol series
BROUILLARD-POICHET, AGNES;DEFOIN, ALBERT;STREITH, JACQUES, TETRAHEDRON LETT., 30,(1989) N0, C. 7061-7064
作者:BROUILLARD-POICHET, AGNES、DEFOIN, ALBERT、STREITH, JACQUES
DOI:——
日期:——
Formation of Complex Hydrazine Derivatives via Aza-Lossen Rearrangement
作者:Dilan E. Polat、David D. Brzezinski、André M. Beauchemin
DOI:10.1021/acs.orglett.9b01742
日期:2019.6.21
The development of a broadly applicable procedure for the aza-Lossen rearrangement is reported. This process converts amines into complexhydrazinederivatives in two steps under safe, mild conditions. This method allows the chemoselective formation of N–N bonds, resulting in the synthesis of cyclic and acyclic products while avoiding side reactions of the amphoteric (ambident) nitrogen-substituted