Synthesis of enantioenriched homopropargylic alcohols through diastereoselective SE' additions of chiral allenylstannanes to aldehydes
作者:James A. Marshall、Xiao Jun Wang
DOI:10.1021/jo00030a036
日期:1992.2
Allenylstannanes (S)-4 and (R)-4, available in ca. 90% ee from alkynones 1 through reduction with the LiAlH4-Darvon alcohol or -ent-Darvon alcohol complex, followed by S(N)2' displacement on the derived mesylates (R)-3 or (S)-3 with Bu3SnLi.CuBr.Me2S, readily add to various aldehydes under Lewis acid catalysis to afford optically active homopropargylic alcohols with good to excellent syn diastereoselectivity. With 2-(benzyloxy)propanal (48), MgBr2-catalyzed reactions are highly stereoselective, affording the syn adduct 49 from the (S)-stannane (S)-4 and the anti adduct 52 from the (R)-stannane (R)-4. BF3-promoted additions give mainly or exclusively the syn adducts 49 and 51. Additions of (S)- and (R)-4 to (R)-3-(benzyloxy)-2-methylpropanal (61) yield the syn adducts 62 and 64 as major or exclusive products.
Amination, Aminocarbonylation, and Alkoxycarbonylation of Allenic/Propargylic Pd Intermediates Derived from Nonracemic Propargylic Mesylates: Synthesis of Nonracemic Propargyl Amines, Allenic Amides, and Butenolides
作者:James A. Marshall、Mark A. Wolf
DOI:10.1021/jo960442m
日期:1996.1.1
MARSHALL, JAMES A.;WANG, XIAO-JUN, J. ORG. CHEM., 56,(1991) N, C. 960-969
作者:MARSHALL, JAMES A.、WANG, XIAO-JUN
DOI:——
日期:——
[2,3] Wittig rearrangement of nonracemic propargyl ethers leading to allenes of high stereochemical integrity
作者:James A. Marshall、Edward D. Robinson、Antonio Zapata
DOI:10.1021/jo00286a013
日期:1989.12
Synthetic Routes to Allenic Acids and Esters and Their Stereospecific Conversion to Butenolides
作者:James A. Marshall、Mark A. Wolf、Eli M. Wallace
DOI:10.1021/jo9618740
日期:1997.1.1
19 and 23 with inversion of configuration through treatment with Pd(Ph(3)P)(4), CO, and the appropriate alcohol in THF. These reactions proceeded with ca. 10% or less of racemization. The allenic esters 23 yielded the iodobutenolides 24 by reaction with IBr. Hydrogenolysis to the butenolide 25 was achieved with Pd(PPh(3))(4) and Bu(3)SnH. Alternatively, the allenic acids 27 could be prepared directly