Concise Syntheses of the Natural Products (+)-Sylvaticin and (+)-cis-Sylvaticin
摘要:
Two concise syntheses of the natural products cis-sylvaticin and sylvaticin are reported, using oxidative cyclization methodology as the key step. A sequential solvolysis/hydride shift/intramolecular reduction cascade was used to establish the trans stereochemistry of one of the THF rings of sylvaticin.
作者:Lynda J. Brown、Ian B. Spurr、Stephen C. Kemp、Nicholas P. Camp、Karl R. Gibson、Richard C. D. Brown
DOI:10.1021/ol800767e
日期:2008.6.1
An asymmetrictotalsynthesis of (+)-cis-sylvaticin is described. Key steps include the use of permanganate-mediated oxidativecyclization of 1,5-dienes to synthesize the two major fragments 2 and 3 and a catalytically efficient tethered RCM to unite these THF-containing fragments. In addition, t-BuP 4 base was found to reliably promote rapid alkylation of the butenolide precursor fragment 4.
Total Synthesis of (+)-<i>cis</i>-Sylvaticin: Double Oxidative Cyclization Reactions Catalyzed by Osmium
作者:Timothy J. Donohoe、Robert M. Harris、Jeremy Burrows、Jeremy Parker
DOI:10.1021/ja0660148
日期:2006.10.1
The double oxidative cyclization of dienes is a viable procedure for making complex natural products containing cis-THF units. A double deprotection/double oxidative cyclization strategy using catalytic osmium tetroxide was used to construct the bisheterocyclic core of cis-sylvaticin and ultimately confirm its structure. The natural product was then prepared by a short sequence of reactions that is exceptionally concise: the final route being just 13 linear steps and 19 chemical operations in total.
Concise Syntheses of the Natural Products (+)-Sylvaticin and (+)-<i>cis</i>-Sylvaticin
作者:Timothy J. Donohoe、Robert M. Harris、Oliver Williams、Gráinne C. Hargaden、Jeremy Burrows、Jeremy Parker
DOI:10.1021/ja9049959
日期:2009.9.9
Two concise syntheses of the natural products cis-sylvaticin and sylvaticin are reported, using oxidative cyclization methodology as the key step. A sequential solvolysis/hydride shift/intramolecular reduction cascade was used to establish the trans stereochemistry of one of the THF rings of sylvaticin.