A mild two-step method was used to cleave the lactam ring of the tricyclic intermediate 1. A key racemic amino alcohol precursor 5 for the construction of Et-743 skeleton was synthesized from 1 through four steps in ...A mild two-step method was used to cleave the lactam ring of the tricyclic intermediate 1. A key racemic amino alcohol precursor 5 for the construction of Et-743 skeleton was synthesized from 1 through four steps in total yield of 47%.展开更多
The tricyclic compound 1, a key intermediate of the pentacyclic core of Et 743 and its analogues, was synthesized. Its 11-epimer was found as the product of racemization when BOP was used as the coupling agent, but no...The tricyclic compound 1, a key intermediate of the pentacyclic core of Et 743 and its analogues, was synthesized. Its 11-epimer was found as the product of racemization when BOP was used as the coupling agent, but not when BOP-C1 used in the same reaction. The stereochemistry of both isomers was confirmed on basis of the 1H NMR and NOE-difference spectra.展开更多
文摘A mild two-step method was used to cleave the lactam ring of the tricyclic intermediate 1. A key racemic amino alcohol precursor 5 for the construction of Et-743 skeleton was synthesized from 1 through four steps in total yield of 47%.
文摘The tricyclic compound 1, a key intermediate of the pentacyclic core of Et 743 and its analogues, was synthesized. Its 11-epimer was found as the product of racemization when BOP was used as the coupling agent, but not when BOP-C1 used in the same reaction. The stereochemistry of both isomers was confirmed on basis of the 1H NMR and NOE-difference spectra.
文摘A concise and efficient synthesis of the pentacyclic intermediate 1, as a simple model compound of Ecteinascidin 743 and its analogues, is described.
