500591-01-5Relevant academic research and scientific papers
Formal synthesis of (+/-)-guanacastepene A.
Shi,Hawryluk, Natalie A,Snider, Barry B
, p. 1030 - 1042 (2007/10/03)
A 17 step synthesis of 55, a late intermediate in Danishefsky's guanacastepene A synthesis, has been completed in 4% overall yield. Key features include the use of vinylmagnesium bromide in the Pd-catalyzed coupling with triflate 13 to give triene 16 with
A novel extension of the Stork-Jung vinylsilane Robinson annelation procedure for the introduction of the cyclohexene of guanacastepene
Snider, Barry B,Shi, Bo
, p. 9123 - 9126 (2007/10/03)
A new annelation procedure has been developed in a model system to introduce the cyclohexene ring of guanacastepene. Cyclohexenone 16 is prepared by sequential methylation and alkylation with allylic iodide 15. One-pot epoxidation, protodesilylation and hydrolysis of the THP forms dione 19, which cyclizes with NaOMe to 24 in 57% overall yield. Reduction, Mitsunobu inversion, and selective oxidation of the primary alcohol forms model 29. Phenyldimethylsilyl allylic iodide 36 is easier to make and more stable than trimethylsilyl allylic iodide 6 used by Stork.
