Construction of the A ring of halichomycin via a RCM strategy
摘要:
Attempts to the synthesis of the A ring of halichomycin via ring-closing metathesis (RCM) reaction were investigated. When triene 5 was used as the precursor of cyclization, only unexpected byproduct aldehyde 17 was obtained. When diene 6 was used as the precursor of cyclization, the desired product 20 was obtained in reasonable yield. This work demonstrated that both modification of the substrate and the RCM reaction conditions are important for obtaining the desired 11-membered macrocycle in reasonable yield. (C) 2013 Elsevier Ltd. All rights reserved.
Studies towards the total synthesis of narbonolide: stereoselective preparation of the C1–C10 fragment
作者:C. Prasad Narasimhulu、Javed Iqbal、Khagga Mukkanti、Parthasarathi Das
DOI:10.1016/j.tetlet.2008.02.099
日期:2008.5
An efficient stereoselective synthesis of the C1-C10 fragment of narbonolide is reported. The stereocentres at C2, 3, 4, 5, 8 and 9 in fragment 5 can be generated via an iterative asymmetric acyl-thiazolidinethione aldol reaction, whereas the stereocentre at C6 is installed by means of Myers alkylation. (C) 2008 Elsevier Ltd. All rights reserved.