TY - JOUR
T1 - Steroids and related natural products. Part XCI. Synthesis of the cardenolides canarigenin and uzarigenin
AU - Kamano, Yoshiaki
AU - Pettit, George
AU - Tozawa, Machiko
PY - 1975/1/1
Y1 - 1975/1/1
N2 - From 3β,14-dihydroxy-5β,14β-card-20(22)-enolide (digitoxigenin)(III), new formal total syntheses of canarigenin [3β,14-dihydroxy-14β-carda-4,20(22)-dienolide](IIa) and uzarigenin [3β,14-dihydroxy-5α,14β-card-20(22)-enolide](Ic) have been completed. The route found most convenient involved direct oxidation of digitoxigenin (III) with t-butyl hypochlorite to yield the 4β-chloro-3-ketone (IVb). Dehydrohalogenation to the 4-en-3-one (canarigenone)(V) was followed by selective reduction with lithium hydrido-tri-t-butoxyaluminate to afford canarigenin (IIa) and with lithium borohydride to yield uzarigenin (Ic).
AB - From 3β,14-dihydroxy-5β,14β-card-20(22)-enolide (digitoxigenin)(III), new formal total syntheses of canarigenin [3β,14-dihydroxy-14β-carda-4,20(22)-dienolide](IIa) and uzarigenin [3β,14-dihydroxy-5α,14β-card-20(22)-enolide](Ic) have been completed. The route found most convenient involved direct oxidation of digitoxigenin (III) with t-butyl hypochlorite to yield the 4β-chloro-3-ketone (IVb). Dehydrohalogenation to the 4-en-3-one (canarigenone)(V) was followed by selective reduction with lithium hydrido-tri-t-butoxyaluminate to afford canarigenin (IIa) and with lithium borohydride to yield uzarigenin (Ic).
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U2 - 10.1039/P19750001972
DO - 10.1039/P19750001972
M3 - Article
C2 - 1238419
AN - SCOPUS:0016647353
SP - 1972
EP - 1976
JO - Journal of the Chemical Society, Perkin Transactions 1
JF - Journal of the Chemical Society, Perkin Transactions 1
SN - 1470-4358
IS - 19
ER -