The synthesis of digitoxigenin

A New Approach to the Design of Novel Inhibitors of Na+,K+-ATPase: 17α-Substituted Seco-D 5β-Androstane as Cassaine Analogues

“…The corresponding 15-enolacetate was then ozonized again to give the desired aldehyde 19 (Scheme 2). The seco-D 5β-androstane-17β-carbaldehyde 20 was obtained in a quite similar fashion starting from the 17R-epimer of 14, 19 through a slightly different step sequence (Scheme 1).…”

Designing Total Syntheses

“…Attacks were mounted on other steroids, and in 1948 the stereochemically much more complex steroid estrone was conquered [18]. A spate of syntheses then followed, some of which are chronicled in Table 1-1 [17][18][19][20][21][22][23][24][25][26][27][28]. On examination of these structures, one is immediately impressed with their stereochemical complexity, and it becomes understandable that the solution of these formidable synthetic problems would have been infinitely more difficult without the timely introduction of the concepts of conformational analysis [29].…”

“…Similarly, once any steroid has been totally synthesized, the construction of a new side chain on it to obtain a different class of steroid represents a formal total synthesis of that class member. The conversion of epiandrosterone to tigogenin and neotigogenin [27] is an example of a formal total synthesis, inasmuch as epiandrosterone had been synthesided previously [20]. Similarly, other formal total syntheses include solasodine [30] and hecogenin [31] from diosgenin, tomatidine from neotigogenin [32], conessine from pregnenolone [33], lanosterol and agnosterol from cholesterol [22], digitoxigenin from 3ß-hydroxy-5ß-androstan-17-one [28], veratramine [34], bufalin and resibufogenin [35].…”

Steroids and related natural products. LIV. Bufadienolides. 7. Synthesis of 3.beta.-acetoxy-5.alpha.-l4.alpha.-bufa-20,22-dienolide

“…(b) N. P. Shusherina, E. A, Luk'yanets, T. L. Tsilevich, and R. Ya Levina, J. Org, Chem. USSR, 2, 1194(1966. (c) R. B. Woodward, F. Sondheimer, D. Taub, K. Heusler, and W, M. McLamore, J. Amer.…”