Short Stereoselective Synthesis of α-Substituted γ-Lactams
作者:Bhooma Raghavan、Rodney L. Johnson
DOI:10.1021/jo052212q
日期:2006.3.1
A concise, stereoselectivesynthesis of α-substitutedγ-lactams is reported. γ-Lactam scaffolds 2 and 3, possessing an Evans' chiral auxiliary and two types of N substituents, were successfully alkylated with different electrophiles to give α-substitutedγ-lactams with reasonable diastereoselectivities. The use of a masked carboxymethyl function off the lactam nitrogen provided a convergent means to
Nonracemizable Isocyanoacetates for Multicomponent Reactions
作者:Alexander G. Zhdanko、Valentine G. Nenajdenko
DOI:10.1021/jo802420c
日期:2009.1.16
Chiral ortho esters of a-isocyano acids were synthesized from commercially available Cbz-protected alpha-amino acids. These compounds are stable toward racemization in the Ugi 4CC in contrast to known esters of alpha-isocyano acids. Applying them in Ugi 4CC with subsequent deprotection gives access to dipeptides with preserved configuration at the C-terminal amino acid.