A total synthesis of the sesquiterpene quinone metachromin-A
作者:Wanda P. Almeida、Carlos Roque D. Correia
DOI:10.1016/s0040-4039(00)76220-4
日期:1994.2
The first totalsynthesis of the marine natural product metachromin A was accomplished through a convergent synthesis amenable to the preparation of synthetic analogues. The main features of this synthesis are the introduction of the oxygenation at C17 employing a Thiele acetoxylation reaction and a stereoselective Horner-Wadsworth-Emmons coupling of a nonstabilized phosphonate with a methyl ketone
Six newsesquiterpenoid quinones with an amino acid residue, metachromins L–Q (1–6), have been isolated from an Okinawanmarinesponge Spongia sp. The structures and stereochemistry of 1–6 were elucidated on the basis of the spectroscopic data and chemical correlations. Metachromins L (1) and M (2) showed modest cytotoxicity.
The antineoplastic agent (−)-metachromin A (1) from Hippospongia metachromia has been synthesized in enantiomerically pure form in 13% overall yield. A general convergent synthetic strategy for different metachromins using a 2-alkyloxy-3-sulfonyl-1,3-oxazolidine as a chiral dithienium equivalent is presented.
来自 Hippospongia metachromia 的抗肿瘤剂 (-)-metachromin A (1) 以对映体纯形式合成,总产率为 13%。提出了使用 2-烷氧基-3-磺酰基-1,3-恶唑烷作为手性二噻吩等价物的不同异色胺的一般收敛合成策略。