241465-95-2

Upstream product

• 98-59-9 p-toluenesulfonyl chloride 
• 125613-63-0 Acetic acid (2S,4aS,4bS,6aS,6bR,9aS,10aS,10bR,12aS)-8-((R)-4-hydroxy-3-methyl-butyl)-4a,6a,7-trimethyl-6-oxo-2,3,4,4a,4b,5,6,6a,6b,9a,10,10a,10b,11,12,12a-hexadecahydro-1H-9-oxa-pentaleno[2,1-a]phenanthren-2-yl ester 
• 915-35-5 hecogenin acetate 
• 241465-82-7 Dichloro-acetic acid (R)-4-((2S,4aS,4bS,6aS,6bR,9aS,10aS,10bR,12aS)-2-acetoxy-4a,6a,7-trimethyl-6-oxo-2,3,4,4a,4b,5,6,6a,6b,9a,10,10a,10b,11,12,12a-hexadecahydro-1H-9-oxa-pentaleno[2,1-a]phenanthren-8-yl)-2-methyl-butyl ester 

Relevant academic research and scientific papers

Concurrent ring opening and halogenation of spiroketals

Ring opening of various spiroketals with triphenylphosphine dihalides under neutral conditions produced ω-halo-enolethers in good to excellent yield. The method transformed even the very stable spiroketal of hecogenin acetate at temperatures below any previously reported for such isomerative opening.

Interphylal product splicing: The first total syntheses of cephalostatin 1, the North hemisphere of ritterazine G, and the highly active hybrid analogue, ritterostatin G(N)1(N)1

Convergent total syntheses of the extremely potent cell growth inhibitor cephalostatin 1 and two hybrid analogues, ritterostatins G(N)1(N) and G(N)1(s), have been achieved. Ritterostatin G(N)1(N) displays sub-nanomolar activity in the 60 cell line human t