α,β-不饱和吉马烷型倍半萜内酯的振动圆二色性（VCD）、VCD激子耦合及绝对构型的X射线测定

Vibrational circular dichroism (VCD), VCD exciton coupling, and X-ray determination of the absolute configuration of an α,β-unsaturated germacranolide.

作者信息

Sánchez-Castellanos Mariano, Bucio María A, Hernández-Barragán Angelina, Joseph-Nathan Pedro, Cuevas Gabriel, Quijano Leovigildo

机构信息

Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04510, México, D.F., Mexico.

出版信息

Chirality. 2015 Mar;27(3):247-52. doi: 10.1002/chir.22420. Epub 2015 Jan 30.

DOI:10.1002/chir.22420

PMID:25640191

Abstract

The absolute configuration of was deduced by vibrational circular dichroism together with the evaluation of the Flack and Hooft X-ray parameters. Vibrational circular dichroism exciton coupling, using the carbonyl group signals, confirmed the absolute configuration of . In addition, sodium borohydride reduction of the 11,13-double bond of 6-epi-desacetyllaurenobiolide () yields an almost equimolecular mixture of C11 epimers, while reduction of the same double bond of 6-epi-laurenobiolide () provided almost exclusively the (11S) diastereoisomer .

摘要

通过振动圆二色性以及对弗拉克和胡夫特X射线参数的评估推导了其绝对构型。利用羰基信号的振动圆二色性激子耦合确定了其绝对构型。此外，6-表去乙酰基劳伦双内酯（）的11,13-双键经硼氢化钠还原生成C11差向异构体的几乎等分子混合物，而6-表劳伦双内酯（）的相同双键还原几乎只得到（11S）非对映异构体。