Synthesis of amido-spiro[2.2]pentanes via Simmons-Smith cyclopropanation of allenamides.
A detailed account of Simmons-Smith cyclopropanations of allenamides en route to amido-spiro[2.2]pentanes is described here. While the diastereoselectivity was low when using unsubstituted allenamides, the reaction is overall efficient and general, representing the most direct synthesis of both chemically and biologically interesting amido-spiro[2.2]pentane systems. With alpha-substituted allenamides, while the diastereoselectivity could be improved significantly based on a series of conformational analyses, both mono- and bis-cyclopropanation products were observed. Consequently, several structurally intriguing amido-methylene cyclopropanes could also be prepared.
Lu
Ting
T
Division of Pharmaceutical Sciences and Department of Chemistry, Rennebohm Hall, 777 Highland Avenue University of Wisconsin, Madison, WI 53705-2222, USA.
Hayashi
Ryuji
R
Hsung
Richard P
RP
DeKorver
Kyle A
KA
Lohse
Andrew G
AG
Song
Zhenlei
Z
Tang
Yu
Y
D002384:Catalysis; D003500:Cyclization; D003521:Cyclopropanes / Q000737:chemistry*; D015394:Molecular Structure; D010420:Pentanes / Q000138:chemical synthesis* / Q000737:chemistry; D010777:Photochemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D003521:Cyclopropanes; D010420:Pentanes