Beilstein J. Org. Chem.2013,9, 1179–1184, doi:10.3762/bjoc.9.132
stereoselective sequence involving a Myers alkylation and a Shiepoxidation. Ring-opening of this epoxide with a vinylcopper complex afforded alcohol 26 instead of the expected product 27. An unusual Lewis acid promoted Payne rearrangement of an α-trityloxy epoxide is proposed to account for this outcome
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Keywords: Lewis acid; lyconadin A; Myers alkylation; Payne rearrangement; Shiepoxidation; Introduction
Lyconadin A (1, Figure 1) was isolated from the club moss Lycopodium complanatum in 2001 by Kobayashi and co-workers [1]. Subsequent to this discovery, lyconadins B–F were isolated and characterized [2
migration of the TIPS group. Surprisingly, Shiepoxidation of the NAP ether derivative of 22 was low-yielding (<10%), and ring-opening of the resulting epoxide did not proceed. These results prompted us to swap the bulky TIPS moiety for a smaller TBDPS group, and triether 24 was obtained uneventfully in 77
Beilstein J. Org. Chem.2008,4, No. 48, doi:10.3762/bjoc.4.48
different fluorous PMB tags, was transformed into alkene M-120 and was then followed by two splits. First, each of the two mixtures was subjected to a Shiepoxidation with enantiomeric ketone catalysts. Later, these two mixtures were split again, half being subjected to a Mitsunobu reaction and the other
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Graphical Abstract
Scheme 1:
Total synthesis of longifolicin by Marshall’s group.