Stereocontrolled Generation of Benzo[a]- and Indolo[2,3-a]quinolizidines from (S)-Tryptophanol and (S)-(3,4-Dimethoxyphenyl)alaninol-Derived Lactams

作者：Perez Maria; Arioli Federica; Rigacci Gianna; Santos Maria M M; Gomez Esque Arantxa; Florindo Pedro; Ramos Carlos; Bosch Joan; Amat Mercedes^*

来源：European Journal of Organic Chemistry, 2011, 20-21: 3858-3863.

DOI：10.1002/ejoc.201100294

• Nitrogen heterocycles
• Alkaloids
• Cyclization
• Isomerization
• Lactams

The stereochemical outcome of Pictet-Spengler cyclizations of (S)-tryptophanol and (S)-(3,4-dimethoxyphenyl)alaninol-derived lactams is discussed. When using HCl the respective trans-H-6/H-12b (or H-11b) indolo[2,3-a]- or benzo[a]quinolizidines are stereoselectively formed, whereas BF(3)center dot Et(2)O-promoted cyclizations lead to trans-H-6/H-11b benzo[a]quinolizidines but cis-H-6/H-12b indolo[2,3-a]quinolizidines. The intermediacy of an oxazolinium salt in the latter process is demonstrated.

• 出版日期2011-7
• 单位河北医科大学