Beilstein J. Org. Chem.2018,14, 1–10, doi:10.3762/bjoc.14.1
hydrolysis of the bisdioxines proceeds through the addition of water to a C=C double bond and results in a second transannular oxa-Michael-type reaction and generation of tetraoxaadamantanes 5. This reaction is decarboxylative when free carboxylic acid functions are present in the bisdioxines, thus forming
21 and 22, but carboxylic acid derivatives are preserved to yield compounds 20, 23, 25, 28, and 29. A hydrogenolysis of the dibenzyl ester 23 yields the free dicarboxylic acid 24. The tetraoxaadamantanes are formed in high yields (65–95%) in most cases, but the addition of water to the concave inside
of the bisdioxines becomes severely hindered in cyclic derivatives, so that the 38-membered ring compound 32 requires microwave heating at 170 °C to form tetraoxaadamantane 33, and the catenated compound 36 and calix[6]arene derivative 37 did not form tetraoxaadamantanes. The reaction mechanisms of
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Graphical Abstract
Scheme 1:
Synthetic routes to 2,4,6,8-tetraoxaadamantanes.
Beilstein J. Org. Chem.2012,8, 738–743, doi:10.3762/bjoc.8.83
reduced nitro derivative 12 as an impurity (Scheme 3).
A remarkable reaction is the ready conversion of macrocyclic as well as open-chain bisdioxine derivatives to 2,4,6,8-tetraoxaadamantanes on acid hydrolysis [4][7][15]. This transformation was also achieved with the dinitro compound 8, which yielded
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Graphical Abstract
Scheme 1:
Synthesis of macrocyclic bisdioxine derivatives (R,S-form of 4 and S-form of 5 shown; see Supporting Information File 1 for deta...