5821-04-5

Upstream product

• 108-24-7 acetic anhydride 
• 10007-76-8 (25R)-5α-spirostan-3β,12β-diol diacetate 
• 74131-95-6 dihydrosolanaviol 
• 74131-93-4 (22R, 25R)-spirosol-5-ene-3β,12β-diol 
• 467-55-0 hecogenin 
• 545-77-7 3β,12β-dihydroxy-(25R)-5α-spirostane 

Downstream Products

• 164530-20-5 C₅₀H₇₀O₇Si₂ 
• 5767-80-6 3β-Hydroxy-12β-acetoxy-Δ¹⁶-5α-pregnenon-(20) 

Relevant academic research and scientific papers

Application of the Reich Iodoso syn-Elimination for the Preparation of an Intermediate Appropriate for the Synthesis of both Hexacyclic Steroidal Units of Cephalostatin 7.

Hecogenin actetate 5 was converted to an intermediate suitable for construction of both "North" and "South" hexacyclic spiroketals present in cephalostatin 7.The key chemical transformations involved are: (1) the Reich iodoso syn-elimination of iodine 18; (2) Rhodium catalyzed intermolecular oxygen alkylation of secondary neopentyl alcohol 21; and (3) Intramolecular Wadsworth-Emmons reaction to provide the ester precursor of aldehyde 4.

Oxidative fragmentation of pregna-14,16-dien-20-ones to 14 beta-hydroxyandrost-15-en-17-ones.

Two methods have been developed for efficient conversion of pregna-14,16-dien-20-ones into 14 beta-hydroxyandrost-15-en-17-ones. One procedure consists of treatment of the ring-D dienone successively with sodium borohydride and singlet oxygen. The reaction is illustrated by the conversion of pregna-14,16-dien-20-one 1 into 14 beta-hydroxyandrost-15-en-17-one 3, via the corresponding allylic alcohol 2. Although this two-step procedure is simple, it provides 3 in relatively low yield, accompanied by a smaller amount of the isomeric 14 alpha-hydroxyandrost-15-en-17-one 6. An alternative one-step conversion is achieved by treatment of dienone 1 with a peroxyacid in the presence of a strong protic acid. This process is illustrated by the two-step conversion of dienone 1 into hydroxy ketone 11 in 51% overall yield (Scheme 5) and by the analogous conversion of dienone 13 into hydroxy ketone 24 in 61% overall yield (Scheme 11).

α,β-epoxy vinyl triflates in Pd-catalyzed reactions

(matrix presented) Reactions of steroidal αβ-epoxy vinyl triflates in Pd-catalyzed reactions are described. Oxidative insertion of Pd0 into the C-O bond, giving vinylpalladium 12, is faster than formation of the π-allyl derivative from the vinyl epoxide. Although 12 can be trapped under certain conditions, it eventually rearranges to palladium alkoxide 14, which is in equilibrium with 15 and/or 10.